Evaluation of extracellular polymeric substances matrix volume, surface roughness and bacterial adhesion property of oral biofilm

Design and evaluation of an MMP-9-responsive hydrogel for vital pulp therapy

OBJECTIVE

To design and evaluate a matrix metalloproteinase 9 (MMP-9)-responsive hydrogel for vital pulp therapy.

METHODS

A peptide linker with optimized sensitivity toward MMP-9 was crosslinked with 4-arm poly (ethylene glycol)-norbornene (PEG-NB) by thiol-norbornene photo-polymerization. This resulted in the formation of a hydrogel network in which the peptide IDR-1002 was incorporated. Hydrogel characterization and gelation kinetics were examined with Fourier-transform infrared spectroscopy, scanning electron microscopy, rheological testing, and swelling evaluation. Hydrogel degradation was examined through multiple exposure to pre-activated MMP-9, to simulate flare-ups of dental pulp inflammation. The IDR-1002 released from degraded hydrogels was measured with high-performance liquid chromatography. Effect of IDR-1002 released from hydrogels on one-week-old multispecies oral biofilms was evaluated using confocal laser scanning microscopy.

RESULTS

MMP-9-responsive, injectable, and photo-crosslinkable hydrogels were successfully synthesized. When hydrogel degradation and release of IDR-1002 were examined with exposure to pre-activated MMP-9, IDR-1002 release was significantly correlated with elevated levels of MMP-9 (p < 0.05). The effectiveness of IDR-1002 in killing bacteria in multispecies oral biofilms was significantly enhanced when the hydrogels were immersed in 10 nM or 20 nM pre-activated MMP-9, compared to immersion in phosphate-buffered saline (p < 0.05).

CONCLUSIONS

The MMP-9-responsive hydrogel is a promising candidate for on-demand delivery of bioactive agent in vital pulp therapy.

CLINICAL SIGNIFICANCE

MMP-9 is one of the most important diagnostic and prognostic biomarkers for pulpitis. An MMP-9-responsive hydrogel has potential to be used as an in-situ on-demand release system for the diagnosis and treatment of dental pulp inflammation.

Characterization and morphological methods for oral biofilm visualization: where are we nowadays?

The oral microbiome represents an essential component of the oral ecosystem whose symbiotic relationship contributes to health maintenance. The biofilm represents a state of living of microorganisms surrounding themselves with a complex and tridimensional organized polymeric support and defense matrix. The substrates where the oral biofilm adhere can suffer from damages due to the microbial community metabolisms. Therefore, microbial biofilm represents the main etiological factor of the two pathologies of dental interest with the highest incidence, such as carious pathology and periodontal pathology. The study, analysis, and understanding of the characteristics of the biofilm, starting from the macroscopic structure up to the microscopic architecture, appear essential. This review examined the morphological methods used through the years to identify species, adhesion mechanisms that contribute to biofilm formation and stability, and how the action of microbicidal molecules is effective against pathological biofilm. Microscopy is the primary technique for the morphological characterization of biofilm. Light microscopy, which includes the stereomicroscope and confocal laser microscopy (CLSM), allows the visualization of microbial communities in their natural state, providing valuable information on the spatial arrangement of different microorganisms within the biofilm and revealing microbial diversity in the biofilm matrix. The stereomicroscope provides a three-dimensional view of the sample, allowing detailed observation of the structure, thickness, morphology, and distribution of the various species in the biofilm while CLSM provides information on its three-dimensional architecture, microbial composition, and dynamic development. Electron microscopy, scanning (SEM) or transmission (TEM), allows the high-resolution investigation of the architecture of the biofilm, analyzing the bacterial population, the extracellular polymeric matrix (EPS), and the mechanisms of the physical and chemical forces that contribute to the adhesion of the biofilm to the substrates, on a nanometric scale. More advanced microscopic methodologies, such as scanning transmission electron microscopy (STEM), high-resolution transmission electron microscopy (HR-TEM), and correlative microscopy, have enabled the evaluation of antibacterial treatments, due to the potential to reveal the efficacy of different molecules in breaking down the biofilm. In conclusion, evidence based on scientific literature shows that established microscopic methods represent the most common tools used to characterize biofilm and its morphology in oral microbiology. Further protocols and studies on the application of advanced microscopic techniques are needed to obtain precise details on the microbiological and pathological aspects of oral biofilm.

Endodontic Treatment of a Dilacerated Maxillary Second Premolar With a Severely Curved Root Canal: A Case Report and Literature Review

Dilaceration is a developmental anomaly characterized by a sharp change in the axial inclination between the crown and the root of a tooth. Severe root curvature in a dilacerated tooth can greatly complicate root canal treatment. This case report details the successful endodontic treatment of a dilacerated maxillary second premolar with significant root curvature. It highlights the importance of a thorough understanding of root canal anatomy and demonstrates the effectiveness of using pre-curved hand files along with heat-treated nickel-titanium rotary instruments in navigating complex root structures to achieve successful treatment outcomes.

Endodontic Treatment of a Mandibular Second Molar Featuring Vertucci Type V Configuration in the Distal Root: A Case Report

Successful root canal treatment relies primarily on thorough shaping, cleaning, and filling of the entire root canal system. Neglecting even a single canal can significantly raise the risk of post-treatment apical periodontitis. While the distal root of mandibular second molars typically has one canal, they can also present with anatomical variations, including the presence of a Vertucci Type V configuration. This article discusses a case in which a Vertucci Type V configuration in a mandibular second molar was effectively identified and treated.

Endodontic Treatment of a Maxillary Second Molar With Five Canals: A Case Report and a Literature Review

A thorough understanding of both common and uncommon root canal anatomies is crucial for the success of root canal treatments, as missing a canal can lead to treatment failure. Although the maxillary second molar typically features three canals, the occurrence of five canals, particularly a mesial buccal third canal (MB3) canal in the mesiobuccal root, is extremely rare. This case report documents such a rare occurrence in a maxillary second molar with five canals. With the assistance of a dental operating microscope, all canals were successfully located, and root canal preparation, irrigation, and filling were accomplished. This case report underscores the significance of in-depth knowledge of root canal anatomy and the invaluable aid of a dental operating microscope in achieving successful root canal treatments.

Sodium hypochlorite against Enterococcus faecalis biofilm in dentinal tubules: effect of concentration, temperature, and exposure time

This study aimed to evaluate the effectiveness of two sodium hypochlorite concentrations at different exposure times and temperatures against Enterococcus faecalis biofilms of varying ages in human dentinal tubules. Dentin blocks were infected with E. faecalis for either 3 days or 3 weeks of incubation. Subsequently, the samples were exposed to sterile water, 2%, and 5.25% sodium hypochlorite for 3 and 10 min at 20 °C and 60 °C . Viability staining and confocal laser scanning microscopy were used to assess the proportion of killed bacteria in the dentinal tubules after exposure. There are no significant differences in the efficacy of E. faecalis killing between 2% sodium hypochlorite at 60 °C for various exposure times and 5.25% sodium hypochlorite at different temperatures or exposure times (P > 0.05). When both solutions were compared at the same temperatures with a 10-min exposure time, no significant differences in the effectiveness of E. faecalis killing between 2% and 5.25% sodium hypochlorite were observed (P > 0.05). To optimize the effectiveness of sodium hypochlorite in killing E. faecalis while minimizing potential damage to root dentin and soft tissue, clinicians should prioritize increasing the temperature or exposure time of sodium hypochlorite, rather than raising its concentration.

Nanofibers of N,N,N-trimethyl chitosan capped bimetallic nanoparticles: Preparation, characterization, wound dressing and in vivo treatment of MDR microbial infection and tracking by optical and photoacoustic imaging

Recent advancements in wound care have led to the development of interactive wound dressings utilizing nanotechnology, aimed at enhancing healing and combating bacterial infections while adhering to established protocols. Our novel wound dressings consist of N,N,N-trimethyl chitosan capped gold‑silver nanoparticles (Au-Ag-TMC-NPs), with a mean size of 108.3 ± 8.4 nm and a zeta potential of +54.4 ± 1.8 mV. These optimized nanoparticles exhibit potent antibacterial and antifungal properties, with minimum inhibitory concentrations ranging from 0.390 μg ml-1 to 3.125 μg ml-1 and also exhibited promising zones of inhibition against multi-drug resistant strains of S. aureus, E. coli, P. aeruginosa, and C. albicans. Microbial transmission electron microscopy reveals substantial damage to cell walls and DNA condensation post-treatment. Furthermore, the nanoparticles demonstrate remarkable inhibition of microbial efflux pumps and are non-hemolytic in human blood. Incorporated into polyvinyl alcohol/chitosan nanofibers, they form Au-Ag-TMC-NPs-NFs with diameters of 100-350 nm, facilitating efficient antimicrobial wound dressing. In vivo studies on MDR microbial-infected wounds in mice showed 99.34 % wound healing rate within 12 days, corroborated by analyses of wound marker protein expression levels and advanced imaging techniques such as ultrasound/photoacoustic imaging, providing real-time visualization and blood flow assessment for a comprehensive understanding of the dynamic wound healing processes.

Comparation of the effectiveness of conventional needle irrigation and photon-induced photoacoustic streaming with sodium hypochorite in the treatment of teeth with apical periodontitis: a randomized clinical trial

Photon-initiated photoacoustic streaming (PIPS) with an Er: YAG laser has been introduced in root canal treatment to improve irrigation and facilitate the removal of bacteria in the root canal system. This study aimed to compare the antibacterial effectiveness of two different root canal irrigation techniques, conventional needle irrigation (CNI) and PIPS, using 1% sodium hypochlorite (NaOCl), in the treatment of teeth with apical periodontitis. Sixty patients with a total of sixty teeth affected by apical periodontitis were included in this study. The teeth underwent root canal therapy, and after mechanical instrumentation, they were randomly assigned to two groups (n = 30) based on the final irrigation protocol: CNI or PIPS with 1% NaOCl. Bacterial suspensions in the root canals were evaluated using Adenosine 5'-triphosphate (ATP) assay kit after mechanical instrumentation and after final irrigation. Then, a follow-up was conducted after 7 days. The results revealed that final irrigation significantly reduced ATP values in both the CNI and PIPS groups (P < 0.001). The ATP values after final irrigation was greater in the CNI group compared to the PIPS group (P < 0.001). After a 7-day follow-up, percussion tenderness and fistula were significantly resolved in both groups (P < 0.05). A multivariate linear regression model was used to identify the factors that influence post irrigation ATP values. The analysis demonstrated that pre-operative percussion tenderness (P = 0.006), the presence of a fistula (P < 0.001) and the method used in the final irrigation (P < 0.001) had a significant impact on the ATP value after final irrigation. These results indicate that employing PIPS with 1% NaOCl as the final irrigation protocol exhibited superior antibacterial effectiveness and has the potential to enhance clinical outcomes in the treatment of teeth afflicted with apical periodontitis.

The Influence of Nickel-Titanium (Ni-Ti) Rotary Instrument Systems on Debris and Smear Layer Formation in Endodontic Procedures: An In Vitro Scanning Electron Microscopy Study

Background Successful endodontic treatment relies on the effective removal of debris and the prevention of smear layer formation within the root canals. The choice of nickel-titanium (Ni-Ti) rotary instrument systems can significantly impact these outcomes. Aim This study aims to evaluate and compare the debris and smear layer formation in root canals of extracted mandibular second premolar teeth following instrumentation with the ProTaper Universal (Dentsply Sirona, Charlotte, NC) (Group II), Twisted File (Kerr Endodontics, Gilbert, AZ) (Group III), and XP Endo (FKG Dentaire, La Chaux-de-Fonds, Switzerland) (Group IV) Ni-Ti rotary instrument systems. Methods In this in vitro study, 60 extracted mandibular second premolar teeth were randomly divided into four groups, each containing 15 teeth. Group I served as the control with no instrumentation. Groups II, III, and IV were instrumented with the ProTaper Universal rotary file, the Twisted File, and the XP Endo file systems, respectively. Debris and smear layer formation were evaluated through scanning electron microscopy (SEM), and photomicrographs were scored using a standardized index. Results Group II (ProTaper) exhibited the highest mean debris and smear layer scores, with values of 3.50 and 2.70, respectively. Group IV (XP Endo) demonstrated the least debris and smear layer formation, with mean scores of 2.65 and 2.08, respectively. Statistical analysis confirmed significant differences among the groups for both debris and smear layer formation. Conclusion The results highlight the practical importance of selecting appropriate Ni-Ti rotary instrument systems to minimize debris and smear layer formation during endodontic procedures. The XP Endo file system showed promise as a favorable choice in this regard, but further clinical research is needed to validate these findings.

Endodontic Treatment of Two Calcified Mandibular Central Incisors: A Case Report

Treating calcified root canals presents significant challenges, as incorrect approaches can result in treatment failure or lead to complications. The necessity for advanced diagnostic and therapeutic tools is often paramount in these situations. This case report demonstrates the successful treatment of two calcified mandibular central incisors, followed up for a period of up to six years. It emphasizes the effectiveness of integrating cone-beam computed tomography, dental operating microscopes, and ultrasonic instruments in the treatment of such challenging cases.

Endodontic Treatment of a Maxillary First Molar With Two Separate Palatal Roots: A Case Report

Maxillary first molars exhibit considerable anatomical variation, with a single palatal root being the most common occurrence, while two palatal roots are notably less frequent. This case report details the endodontic treatment of a maxillary first molar with two separate palatal roots. It highlights the critical importance of recognizing these anatomical variations and their unique challenges during endodontic procedures. This report emphasizes the essential role of advanced diagnostic methods, such as cone-beam computed tomography, and the use of microscopic techniques in identifying and treating such cases.

Endodontic Retreatment of a Mandibular Second Molar With a C-shaped Root Canal Configuration: A Case Report

Root canal retreatment in mandibular second molars with C-shaped root canal configurations presents notable challenges. This article presents a case of successful root canal retreatment in a mandibular second molar exhibiting this complex configuration. Achieving a successful endodontic outcome in such cases necessitates a comprehensive understanding of the unique root canal anatomy. Moreover, the employment of advanced instruments and techniques is crucial to effectively address the intricacies of the C-shaped root canal system.

Locating and Treating Three Calcified Canals in a Mandibular First Molar With Radix Entomolaris and Five Canals: A Case Report

The success of root canal treatment is highly contingent on the comprehensive shaping, cleaning, and filling of the entire root canal system. Failure to address one or more canals often results in an increased likelihood of post-treatment apical periodontitis. Typically, mandibular first molars feature two roots and three canals, but they may also exhibit anatomical variations, such as a mesial middle canal or radix entomolaris (RE). This article presents a case where three calcified canals in a mandibular first molar with RE and five canals were successfully located and treated.

An In Vitro Study: Does Adding Iodine Potassium Iodide and Cetrimide to Calcium Hydroxide Paste Enhance Its Antimicrobial Effect Against Oral Biofilms?

Objectives This study aimed to evaluate the antibiofilm effect of calcium hydroxide (CH), 0.5% iodine potassium iodide (IKI), and 0.5% cetrimide (CTR), alone and in combinations on one-week and three-week-old biofilms. Materials and methods Gingival plaque was collected, and biofilms were grown in vitro anaerobically. Biofilms were exposed to each of the three medicaments and their combinations for one day, one week, and two weeks. Proportions of dead and live bacteria in the biofilms were evaluated. Results The killing of bacteria by different medicaments in the three-week-old biofilm was lower than in the one-week-old biofilm (p<0.05). The efficacy of IKI and CTR in killing bacteria was weaker than that of CH, but the highest efficacy in killing was achieved when all three were combined (p<0.05). There was no significant difference in the antibiofilm effect between a day's exposure to the mixture of the three medicaments and one or two weeks of treatment with CH alone (p>0.05). Conclusions Three-week-old biofilms are more resistant to medicaments than one-week-old biofilms. Combining IKI and CTR with CH resulted in a stronger antibiofilm effect than using CH alone. Mixing the three medicaments may enable obtaining the desired clinical effect in a shorter exposure time.

Comparative Evaluation of Bacterial Reduction by Laser-Activated Irrigation Technique (LAI) With Conventional Needle Irrigation (CNI) in Single-Rooted Teeth With Pulpal Necrosis: A Single-Blinded Randomized Controlled Trial

Aim  To compare the bacterial reduction in single-rooted teeth with pulpal necrosis after laser-activated irrigation technique (LAI) and conventional needle irrigation (CNI). Methodology In this clinical trial (CTRI/2021/09/047767), 32 patients with pulpal necrosis were enrolled. Under complete aseptic conditions, access cavity preparation was done and the baseline sample S1 was collected from the root canal using paper points. After chemo-mechanical preparation they were allocated into two groups, following block randomization; Group A - CNI with 27 gauge side-vented needle, Group B - LAI with pulsed Er,Cr:YSGG (erbium, chromium:yttrium-scandium-gallium-garnet) (2780 nm) laser. After irrigant activation, canals were dried and a second sample S2 was taken using paper points. Microbial analysis using quantitative polymerase chain reaction (qPCR) was done to quantify the bacterial reduction among the two groups. Inter-group and intra-group analysis was done using the independent student t-test and Bonferroni test, respectively. The data was represented in terms of quantification cycle (Cq) values, which are inversely proportional to the microbial count.  Results There was no significant difference in S1 between the two groups (mean difference=0.0205; p=0.912). There was a significant difference in S2 between the two groups for the organisms (mean difference=0.8042; p=0.000). The mean percentage of bacterial reduction in CNI was 10.82% and in LAI it was 25.92%.  There was a significant difference in S1 through S2 within the two groups for the organisms (p=0.000). The mean difference of Cq value is high for LAI compared to CNI (1.3494).  The fold change was calculated by taking the ΔCq value and ΔΔCq value after the logarithmic transformation of the Cq value. LAI showed lower levels of DNA at S2 similar to CNI. There is no significant difference in mean fold change between CNI and LAI (p=0.564).  Conclusion This clinical trial concluded that both LAI and CNI were effective in bacterial reduction. There was greater bacterial reduction with LAI (25.92%) than with the CNI (10.82%) in single-rooted teeth with pulpal necrosis using qPCR analysis.

Evaluation of anti-biofilm effect of antimicrobial sonodynamic therapy-based periodontal ligament stem cell-derived exosome-loaded kojic acid on Enterococcus faecalis biofilm

Introduction. Antimicrobial sonodynamic therapy (aSDT) is an approach that uses ultrasound waves (UWs) and a sonosensitizer to generate reactive oxygen species (ROS) to damage microbial cells in biofilms. Using nano-carriers, such as exosomes (Exos), to deliver the sonosensitizer can potentially enhance the effectiveness of aSDT.Hypothesis/Gap Statement. aSDT can downregulate the expression of gelE and sprE genes, increasing the production of endogenous ROS and degradation of pre-formed Enterococcus faecalis biofilms.Aim. This study investigated the anti-biofilm effect of aSDT-based periodontal ligament stem cell-derived exosome-loaded kojic acid (KA@PDL-Exo) on pre-formed E. faecalis biofilms in root canals.Methodology. Following the isolation and characterization of PDL-Exo, KA@PDL-Exo was prepared and confirmed. The minimal biofilm inhibitory concentration (MBIC) of KA, PDL-Exo, KA@PDL-Exo and sodium hypochlorite (NaOCl) was determined, and their anti-biofilm effects were assessed with and without UWs. The binding affinity of KA with GelE and SprE proteins was evaluated using in silico molecular docking. Additionally, the study measured the generation of endogenous ROS and evaluated changes in the gene expression levels of gelE and sprE.Results. The results revealed a dose-dependent decrease in the viability of E. faecalis cells within biofilms. KA@PDL-Exo was the most effective, with an MBIC of 62.5 µg ml-1, while NaOCl, KA and PDL-Exo had MBIC values of 125, 250 and 500 µg ml-1, respectively. The use of KA@PDL-Exo-mediated aSDT resulted in a significant reduction of the E. faecalis biofilm (3.22±0.36 log10 c.f.u. ml-1; P<0.05). The molecular docking analysis revealed docking scores of -5.3 and -5.2 kcal mol-1 for GelE-KA an SprE-KA, respectively. The findings observed the most significant reduction in gene expression of gelE and sprE in the KA@PDL-Exo group, with a decrease of 7.9- and 9.3-fold, respectively, compared to the control group (P<0.05).Conclusion. The KA@PDL-Exo-mediated aSDT was able to significantly reduce the E. faecalis load in pre-formed biofilms, decrease the expression of gelE and srpE mRNA, and increase the generation of endogenous ROS. These findings imply that KA@PDL-Exo-mediated aSDT could be a promising anti-biofilm strategy that requires additional in vitro and in vivo investigations.

Full Pulpotomy as a Treatment for Irreversible Pulpitis in Permanent Teeth: A Systematic Review of the Literature Based on Case Reports

The objective of this systematic review was to evaluate the current evidence of case reports where the treatment for permanent teeth with a diagnosis of irreversible pulpitis was a full pulpotomy. This study was carried out by two reviewers following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A systematic electronic search was carried out in the PubMed, Google Scholar, and Scopus databases until the year 2022 to find articles in English where the treatment for irreversible pulpitis in permanent teeth was a full pulpotomy. Literature reviews, in vitro or animal studies, abstracts, and unpublished data were excluded. The intervention, control, and outcome parameters were selected following the "Population, Interventions, Control, and Outcome" (PICO) guidelines. A total of 636 articles were found, and 14 articles were selected to be included in this review. The selected articles describe cases of full pulpotomies in mature permanent teeth with a diagnosis of irreversible pulpitis with a total of 34 (100%) successful cases, where 18 were men and 16 were women, with an average age of 19.20 ± 10.59 years and an average follow-up of 35.82 ± 26.39 months, with 12 months being the minimum follow-up time. The material used most frequently for obturation of the full pulpotomy was mineral trioxide aggregate in 16 cases (47.06%). Within the limitations of this review, full pulpotomy presents a high success rate regardless of the tooth, age, or sex as a treatment for teeth diagnosed with irreversible pulpitis.

Effects of DJK-5 and chlorhexidine on exopolysaccharide volume and pH in oral biofilms

BACKGROUND

Exopolysaccharides (EPS) are essential constituents of the extracellular matrix within oral biofilms and are significantly influenced by the local microenvironment. This study aimed to investigate the impact of two distinct antimicrobial agents, DJK-5 and chlorhexidine (CHX), on the EPS volume and pH levels in oral biofilms.

METHODS

Oral biofilms obtained from two donors were cultured on hydroxyapatite discs for durations of 3 days, 1 week, 2 weeks, 3 weeks, and 4 weeks. Subsequently, these biofilms were subjected to treatment with 10 µg/mL DJK-5 or 2% CHX for 3 min. The impact of these antimicrobial treatments on factors such as the proportion of dead bacterial, in situ pH, and EPS volume within the biofilms was assessed using corresponding fluorescent probes. The examination was carried out utilizing confocal laser scanning microscopy, and the resulting images were analyzed with a focus on the upper and lower layers of the biofilm, respectively.

RESULTS

DJK-5 exhibited a more potent bactericidal effect compared to CHX across the 3-day to 4-week duration of the biofilm (P < 0.05). The biofilms were acidic, with the upper layer being less acidic than the lower layer (P < 0.05). Both antimicrobial agents increased the pH, but DJK-5 had a greater effect than CHX (P < 0.05). The volume of EPS was significantly lower in DJK-5 treated biofilms compared to that of CHX, regardless of age or layer (P < 0.05).

CONCLUSION

DJK-5 exhibited superior effectiveness in reducing viable bacteria and EPS volume, as well as in raising extracellular pH, as compared to chlorhexidine.

Periapical Lesions and Missed Canals in Endodontically Treated Teeth: A Cone-Beam Computed Tomographic Study of a Chinese Subpopulation

BACKGROUND Periapical lesions (PL) are a common complication of endodontically treated teeth (ETT), which can result from a missed canal (MC). This study aimed to assess the prevalence of PL and MC in the ETT of a Chinese subpopulation and investigate potential associations between them. MATERIAL AND METHODS A total of 561 cone-beam computed tomography images were selected and analyzed. A total of 1024 endodontically treated posterior teeth excluding third molars were evaluated for the presence of PL and MC. The chi-square test or Fisher's exact test, as well as the odds ratio test, were used to determine whether there was an association and risk relationship between the incidence of PL and the occurrence of MC. RESULTS The overall prevalence of PL and MC in ETT was 56.1% and 19.0%, respectively. In endodontically treated molars, the incidence of PL and MC was 64.1% and 27.6%, whereas in premolars, it was 42.1% and 4.27%. The maxillary first molar showed the highest frequency of PL (71.5%) and MC (65.7%), with the mesiobuccal second canal being the most missed (78.8%). Teeth with an MC were found to be 3.658 times (95% confidence interval=2.541-5.301, P<0.0001) more likely to be associated with a PL. CONCLUSIONS Endodontically treated teeth with missed canals are associated with higher risks of periapical lesions. The high prevalence of these complications in a Chinese subpopulation underscores the importance of implementing enhanced diagnostic and treatment methods for root canal treatment or retreatment.

Evaluation of the Prevalence of White Spot Lesions During Fixed Orthodontic Treatment Among Patients Reporting for Correction of Malocclusion: A Prevalence Study

BACKGROUND

Despite recent breakthroughs in caries preventive measures, one of the biggest issues clinicians confront is preventing demineralization while undergoing orthodontic therapy. The buildup of plaques around orthodontic brackets over time causes white spot lesions (WSLs). The goal of the present research was to assess the prevalence of WSLs in patients undergoing orthodontic treatment before starting therapy and at six and 12 months into therapy, adopting the visual examination approach.

MATERIALS AND METHODS

We looked for WSLs on tooth surfaces gingival to an archwire because this is the area most likely to experience enamel demineralization during orthodontic treatment. The visual assessment was conducted using the following scale at baseline, six months, and 12 months for orthodontic patients: score 0: no demineralization or noticeable white patches on the surface; score 1: mild demineralization with a visible white spot but no surface disruption; score 2: moderate demineralization with a noticeable WSL that has a roughened surface but does not need repair; and score 3: severe demineralization with a noticeable WSL that needs repair. Fisher's exact test was used after a chi-square analysis to determine whether there were any differences between all three categories (six months, 12 months, and control).

RESULTS

The frequency of WSL in patients at 12 months of orthodontic treatment was 46.57%, while it was 11.86% in patients who just started orthodontic treatment. The difference was statistically significant (p = 0.01), showing that the frequency was greater in patients at 12 months of orthodontic treatment as compared to patients who had just started undergoing orthodontic treatment. The frequency of WSL in patients at six months of orthodontic treatment was 37.34%, while it was 11.86% in patients who just started orthodontic treatment. The difference was statistically significant (p = 0.03), showing that the frequency was greater in patients at six months of orthodontic treatment as compared to patients who had just started undergoing orthodontic treatment. The frequency of WSL in patients at six months of orthodontic treatment was 37.34%, while it was 46.57% in patients at 12 months of orthodontic treatment. The frequency was greater in patients at 12 months of orthodontic treatment as compared to patients at six months of orthodontic treatment; however, the difference was non-significant statistically (p = 0.76).

CONCLUSION

This clinical investigation revealed that the number of WSLs increased significantly during the first six months of treatment and then increased gradually until the final 12 months. During the first few months of treatment, doctors should assess the patients' dental hygiene habits and, if necessary, take further precautions to prevent demineralization.

Cleaning and Disinfecting Oval-Shaped Root Canals: Ex Vivo Evaluation of Three Rotary Instrumentation Systems with Passive Ultrasonic Irrigation

Background and Objectives: Successful root canal treatment depends on the thorough removal of biofilms through chemomechanical preparation. This study aimed to investigate and compare the cleaning and disinfecting efficiency of oval-shaped root canals using XP-endo Shaper (XPS), ProTaper Next (PTN), and HyFlex CM (HCM) in combination with passive ultrasonic irrigation (PUI). Materials and Methods: Ninety extracted teeth were contaminated and randomly divided into three groups: XPS, PTN, and HCM. Each group was assigned to three subgroups: subgroup A (sterile saline), subgroup B (3% sodium hypochlorite and 17% ethylenediaminetetraacetic acid), and subgroup C (3% sodium hypochlorite, 17% ethylenediaminetetraacetic acid, and PUI). Bacterial sampling was conducted both from baseline samples and samples after chemomechanical preparation. Scanning electron microscopy (SEM) was used to evaluate the residue bacterial biofilms, hard tissue debris, and smear layers on the buccolingual walls of oval-shaped root canals. Results: When combined with sterile saline, XPS demonstrated a higher reduction of bacterial counts and was more effective in eradicating Enterococcus faecalis in the middle third of the canals compared to the other instruments (p < 0.05). Additionally, when used with antimicrobial irrigants, XPS was more effective in disinfecting the coronal third of the canals than the other instruments (p < 0.05). Furthermore, XPS reduced hard tissue debris more effectively in the middle third of canals than in the apical third (p < 0.05). Conclusions: XPS outperforms PTN and HCM in disinfecting oval-shaped root canals. Despite the fact that combining XPS and PUI improves cleaning and disinfecting, removing hard tissue debris from the critical apical area remains challenging.