CHX Group Research Articles

Potential of Erythrosine-Mediated Photodynamic Therapy as a Cavity Disinfectant: Antibacterial Efficacy and Bonding Ability

This study aimed to evaluate the antibacterial efficacy of erythrosine-mediated photodynamic therapy (PDT) against <i>Streptococcus mutans</i> (<i>S. mutans</i>) in dentin and its effect on the shear bond strength (SBS) of composite resin to dentin. Eighty extracted human noncarious premolars were used in this study. Forty teeth were used for the antibacterial activity test, while the remaining 40 were used for the SBS test. Both experiments were conducted with 4 experimental groups (n = 10): control (distilled water), sodium hypochlorite (NaOCl, 6%), chlorhexidine (CHX, 0.12%), and erythrosine-mediated PDT. Antibacterial effects were evaluated by counting <i>S. mutans</i> colony-forming units (CFUs). The SBS of composite resins to dentin was measured using a universal testing machine. All treatments (NaOCl, CHX, and PDT) demonstrated statistically significant differences in antibacterial activity compared with the control group (<i>p</i> < 0.05). The antibacterial effects were ranked from strongest to weakest as follows: NaOCl, PDT, and CHX. In the SBS test, the NaOCl group exhibited a statistically significant difference compared with the CHX, PDT, and control groups (<i>p</i> < 0.05), with the lowest bond strength. No statistically significant differences were found among the CHX, PDT, and control groups (<i>p</i> > 0.05). Erythrosine-mediated PDT exhibited significant antibacterial effects against <i>S. mutans</i>, with higher antibacterial activity than CHX but lower than NaOCl. Only NaOCl negatively affected the bond strength of composite resin to dentin. In conclusion, erythrosine-mediated PDT shows potential as a cavity disinfectant due to its significant antibacterial effects against <i>S. mutans</i> and lack of adverse effects on bond strength.

Effect of Using Mouthwash Containing Cibotium barometz J. Smith on Cariogenic Bacteria and Acid-producing Ability of Saliva: A Randomised Blinded Clinical Trial.

To examine the anti-caries effect of mouthwashes containing Cibotium barometz J. Smith (CB), a natural substance, and compare it with chlorhexidine and saline solution. A randomised, blinded clinical trial was conducted on 76 study participants. The differences between the 3 gargle groups (saline gargle: SAL; chlorhexidine gargle: CHX; CB gargle group: CB) and the differences over time (baseline, after 1 week, after 2 weeks) were compared. To this end, ANOVA was performed on caries-related clinical indicators (e.g. O'Leary plaque index, caries activity, and satisfaction). The O'Leary index, caries activity, and saliva tests, gradually improved in group CB at one and two weeks. In the case of bacterial tests, unlike SAL and CHX, only in group CB did the decrease occur one and two weeks later. The caries-related indicators decreased significantly over time in group CB compared to SAL and CHX groups, and there was also a statistically significant difference in interaction between groups and time (p<0.05). The mouthwash containing CB extract showed statistically significant improvement in biofilm adhesion as well as the saliva and bacterial tests compared to SAL and CHX. However, since there were differences in the initial oral conditions of the three groups, additional long-term research is needed through crossover clinical trials to supplement these.

Impact of surface chemical treatment in surgical regenerative treatment of ligature-induced peri-implantitis: A canine study.

Implant surface decontamination is a critical step in peri-implantitis treatment. The aim of this study was to assess the effect chemotherapeutic agents have on reosseointegration after treatment on ligature-inducted peri-implantitis. Six male canines had 36 implants placed and ligatures were placed around them for 28 weeks to establish peri-implantitis. The peri-implant defects were randomly treated by 1 of 3 methods: 0.12% chlorhexidine (CHX test group), 1.5% sodium hypochlorite (NaOCl test group), or saline (Control group). Sites treated with NaOCl and CHX were grafted with autogenous bone, and all sites then either received a collagen membrane or not. Histology sections were obtained at 6 months postsurgery to assess percentage of reosseointegration. Thirty-five implants were analyzed (CHX: 13; NaOCl: 14; Control:8). NaOCl-treated sites demonstrated reosseointegration with direct bone-to-implant-contact on the previously contaminated surfaces (42% mean reosseointegration), which was significantly higher than Controls (p<0.05). Correspondingly, clinical improvement was noted with a significant reduction in probing depth from 5.50±1.24mm at baseline to 4.46±1.70mm at 6-months postsurgery (p=0.006). CHX-treated sites demonstrated a nonsignificant reosseointegration of 26% (p>0.05); however, in the majority of cases, the new bone growth was at a distance from the implant surface without contact. Probing depths did not improve in the CHX group. The use of membrane did not influence reosseointegration or probing depths (all p>0.05). Titanium implants with peri-implantitis have the capacity to reosseointegrate following regenerative surgery. However, treatment response is contingent upon the chemotherapeutic agent selection. Additional chemical treatment with 1.5% NaOCl lead to the most favorable results in terms of changes in defect depth and percentage of reosseointegration as compared to CHX, which may hinder reosseointegration.

Clinical effect of chlorhexidine and sodium fluoride on corrosion behavior and surface topography of nitinol orthodontic archwires

BackgroundAlterations in the mechanical properties of the materials utilized in orthodontic appliances could affect the working properties of the appliances, thereby affecting clinical progress and outcome. Numerous studies have confirmed the correlation between alloy corrosion and raised surface roughness, which has a direct impact on the working characteristics of orthodontic archwires.MethodsThirty nickel-titanium (NiTi) orthodontic archwires were utilized in this study. Patients were randomly selected and allocated into three groups according to the randomization plan; (The control group): subjects practiced regular oral hygiene; (The fluoride group): subjects used fluoride for intensive prophylaxis; (The chlorhexidine group): subjects used chlorhexidine. Representative samples were evaluated by SEM, and then SEM images with high resolution were examined using Image J software to determine the surface roughness and obtain the results for further statistical analysis.ResultsOur findings indicated a significant difference was found between the three groups regarding the anterior and posterior parts between the control and the two other groups and a non-significant difference between NaF and CHX groups. Overall, the p-value for group comparisons was 0.000 for both parts, indicating a highly significant difference especially between the control and NaF groups.ConclusionMouthwashes containing sodium fluoride demonstrated more significant surface alterations than the control and CHX groups and should be prescribed in accordance with orthodontic materials to reduce side effects.

Effectiveness of a tissue conditioner containing antifungals in a rat model of denture stomatitis.

This study investigated the effectiveness of a drug-modified tissue conditioner in an animal model of denture stomatitis. Wistar rats wore a Candida albicans-contaminated palatal device for 4 days. Next, nystatin (Nys) or chlorhexidine (Chx) were added to a tissue conditioner in their raw or β-cyclodextrin-complexed (βCD) forms at their minimum inhibitory concentrations. As controls, one group was not subjected to any procedure (NC), one group used sterile devices, one group had denture stomatitis but was not treated (DS), and another had the devices relined with the tissue conditioner without the addition of any drug (Soft). After 4 days of treatment, treatment effectiveness was assessed visually, histologically, and through CFU count, and myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) assays. Rats from the Soft, Nys, Nys:βCD, and Chx groups presented a significant decrease in the microbial load compared with the untreated group. Treatment groups showed lower MPO and NAG activity compared to the non-treated group. The addition of antifungals to a soft tissue conditioner can be a promising approach for denture stomatitis treatment.

Impact of various solutions on the oral health status of critically ill patients.

Oral care is a crucial challenge of nursing care in orally intubated patients. Oropharyngeal colonization with microorganisms is probably the first step in the pathogenesis of most bacterial pulmonary infections. This study aimed to investigate the effect of different oral care solutions on the oral health status of critically ill patients. We conducted a quasi-experimental study involving a convenience sample of 60 adult orally intubated patients, distributed equally into three groups: 20 patients received 0.12% chlorhexidine gluconate (CHX) solution as an oral rinse; 20 patients received 0.1% hexetidine (HEX) solution as an oral rinse; and a control group of 20 patients received routine hospital oral care with 0.9% normal saline (NS) solution. Oropharyngeal and tracheal cultures were obtained from patients within 24-48 h of admission, before the administration of topical oral antimicrobial solutions and then repeated on day 4 and day 7 after the oral solutions. The study revealed that CHX has a more powerful effect than HEX and NS in improving the oral mucosa and decreasing colonization of both the oropharynx and trachea. On day 7, the improvements were statistically significant in the CHX group and the HEX group (P = 0.02 and P = 0.03, respectively), but not in the NS group. This research confirms the effect of CHX and HEX in lowering the risk of tracheal and oropharyngeal colonization, and recommends the use of a CHX solution as oral mouth care in critically ill patients.

Fabrication of the low-k films with tunable k value as spacers in advanced CMOS technology

In advanced CMOS technology, a suitable spacer scheme is crucial to alleviate the effects of increasing parasitic resistance and capacitance on device performance as the critical dimensions shrinking. Low dielectric constant (low-k) films, possessing a tunable k value ranging from 3.5 to 6.5, were fabricated using plasma-enhanced atomic layer deposition in a single chamber. The fabrication process involved the deposition of the SiN film via SiH2I2 with N2 plasma, as well as the deposition of the SiOX, SiOCN, and SiON films using diisopropylamino silane with O2, Ar/O2, and N2/O2 plasmas, respectively. The introduction of groups containing carbon (C) tended to loosen the film structure, due to its weak bond strength with Si, thus made distinctions in structural and electrical stability. We developed such a process which can adjust the C-group concentration and O, N content to tune the film k value. The SiOx, SiOCN, SiON, and SiN films had high breakdown strength of 9.04, 7.23, 9.41, and over 11 MV cm−1, and meanwhile low leakage current density of 2.42 × 10−9, 4.78 × 10−8, 1.29 × 10−9, and 9.26 × 10−10 A cm−2, respectively. The films exhibited remarkable thermal stability, enhanced breakdown strength, and suppressed leakage with annealing treatment, which could be attributed to the desorption of —CHX groups. Moreover, the low-k materials demonstrated excellent step coverage both in the inner-spacer cavity and on sidewalls, exploring the potential application as spacers in advanced CMOS structure.

Comparison of the effectiveness of Morus alba and chlorhexidine gels as an adjunct to scaling and root planing on stage II periodontitis - A randomized controlled clinical trial.

The present study aimed to assess and compare the effect of Morus alba and chlorhexidine gel as an adjunct to scaling and root planing (SRP) in treating stage II periodontitis. A single-blind, randomized controlled trial was conducted on 180 patients with stage II periodontitis who received full-mouth SRP. They were randomly assigned to receive chlorhexidine digluconate (CHX) gel, Morus alba (MA) and placebo gel for Groups A, B and C, respectively, at the baseline, 15 days and 30 days. Plaque index (PI), Gingival index (GI), periodontal pocket depth (PPD) and quantitative analysis (culture) of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia were assessed at baseline and 45 days. Analysis of variance was used to compare the significant difference in PI, GI, PPD and microbiological parameters between the three groups after the intervention, followed by post hoc Mann-Whitney U and Tukey's HSD test for clinical and microbiological parameters, respectively. Intergroup comparison of the PI, GI and microbiological parameters between the MA and CHX groups at the end of 45 days did not show a statistically significant difference (p > 0.05), whereas a statistically significant difference was observed for PPD between MA and CHX groups with the mean difference of 0.18 mm (p = 0.002). Morus alba gel was found to be effective in decreasing PPD. However, there was no difference between Morus alba and chlorhexidine gel as an adjunct to SRP in treating stage II periodontitis.

Antibacterial, Antibiofilm, and Tooth Color Preservation Capacity of Magnesium Oxide Nanoparticles Varnish (in vitro Study).

Antibacterial and antibiofilm properties of magnesium oxide nanoparticles (MgONPs) mixture assessed against Streptococcus mutans (S. mutans), in addition to examining MgONPs varnish impact on the preservation of the tooth color and inhibition of methylene blue diffusion to the enamel. MgONPs mixture was prepared in deionized water (DW), absolute ethanol (E), and rosin with ethanol (RE), named varnish. The antibacterial and antibiofilm capacities of MgONPs mixtures were tested by agar well diffusion, colony-forming unit (CFU), and biofilm inhibition microtiter methods in triplicate and compared to sodium fluoride varnish (NaF) and chlorhexidine mouthwash (ChX). A spectrophotometer was used to record basic tooth color. The artificial demineralization was initiated for 96 h. Then, experimental materials were applied to the corresponding group, and 10-day pH cycles proceeded. Then, the color was recorded in the same ambient environment. The methylene blue diffusion was evaluated by staining the samples for 24 h. After that, the diffusion test was calculated by a digital camera attached to the stereomicroscope. The agar well diffusion test expressed a significant inhibition zone with all MgONPs mixtures (p = 0.000), and maximum inhibition zone diameter associated with MgONPs-RE. The same finding was observed in the CFU test. Additionally, 2.5%, 5%, and 10% MgONPs-RE varnish showed strong biofilm inhibition capacity (p = 0.039) compared to NaF and ChX groups that inhibit biofilm formation moderately (p = 0.003). The study shows that the 5% MgONPs-RE varnish maintains basic tooth color with minimal methylene blue diffusion compared to NaF varnish (p = 0.00). Evaluating MgONPs as a mixture revealed antibacterial and antibiofilm capacity against S. mutans with a higher effect of MgONPs-RE varnish. Also, examining the topical effect of MgONPs-RE varnish on the preservation of the tooth color after pH cycle challenges and methylene blue diffusion to enamel confirmed the high performance of MgONPs-RE varnish at 5%.

Evaluation of Push-out Bond Strength of Bioceramic Root Canal Sealers with Different Final Irrigation Protocols

This study aims to evaluate the bond strength of bioceramic root canal sealers, with different final irrigation protocols. A total of 104 human upper incisor teeth were selected for applying four different irrigation solutions (Ethylene diamine tetraacetic acid (EDTA), Chlorine Hexidine Gluconate (CHX), Sodium Hypochlorite (NaOCl), and Distilled Water (D.W)) and two root canal sealer protocols (Endosequence BC (BC), Well-Root ST (ST)), in this in vitro study. After root canal treatment specimens were sectioned to three parts (coronal, middle, and apical). Push-out bond strength test was performed in a universal testing machine (Zwick-Roel, Germany) at a crosshead speed of 1 mm/min. Regardless of the irrigation protocol and sealer used, the highest bond strength values were obtained from the apical section ($$p&lt;0.05$$). 5.25% NaOCl + 17% EDTA + 5.25% NaOCl and 2% CHX + 17% EDTA + D.W statistically showed the highest bond strength value and 2% CHX + 17% EDTA + 2% CHX group showed the lowest value in this study ($$p&lt;0.05$$). The bond strength values of Endosequence BC Sealer were statistically higher than the bond strength values of Well Root ST ($$p&lt;0.05$$). According to the final irrigation, Endosequence BC Sealer and Well Root ST root canal sealers showed the highest bonding strength in CHX + EDTA + D.W and NaOCl + EDTA + NaOCl groups.

C7‐Halomethylene/methyl‐C3‐thiophenyl‐spirocyclic‐β‐lactams: Synthesis, X‐ray Analysis, Antimicrobial Evaluation, Cytotoxicity Profile and Molecular Docking Interactions

AbstractIn the realm of healthcare, the continuous evolution of new alternative antimicrobial agents provides hope in addressing the progressively daunting issue of severe multidrug resistance. In our quest to confront drug resistance, we explored the conjugation of thiophene motif with β‐lactams into single matrix to develop a series of spirocyclic‐β‐lactams. For this, stereoselective synthesis of cis‐C3‐alkyloxy‐C4‐thiophenyl substituted monocyclic β‐lactams was achieved which were further subjected to intramolecular sulfenyl‐cyclization to furnish C7‐halomethylene/methyl‐C3‐thiophenyl substituted spirocyclic‐β‐lactams. The synthesized compounds were investigated in vitro for their potential activity against six multidrug‐resistant bacterial strains. The most promising C7‐iodomethylene‐C3‐thiophenyl‐spirocyclic‐β‐lactam 7 a appended with 4′‐methoxyphenyl moiety, exhibited acceptable activity against B. cereus and P. aeruginosa with MIC values of 0.75 and 6.25 μg/mL respectively, surpassing ampicillin and vancomycin. Furthermore, this compound demonstrated antifungal effectiveness against C. tropicalis (1.5 μg/mL). On the basis of substituent type and their respective positions, compounds possessing −OCH3 and −C=CHX (halomethylene) groups exhibited more inhibitory potential than others. Active derivatives tested for their cytotoxicity on normal human hepatic (THLE‐2) cell lines confirmed their non‐toxic nature. Further, molecular docking studies predicted the favourable binding interactions of spirocycles within active sites of target proteins. Moreover, several compounds illustrate satisfactory in silico ADME profile. These outcomes provided bright prospect for development of spirocyclic‐β‐lactams as potential solution to combat evolving multidrug resistance.

Influence of Different Mouthwashes on the Efficacy of Fluoridated Dentifrices in Prevention of Enamel Erosion: An In Vitro Study.

The purpose of the current study was to evaluate the impact of three various mouthwashes on the effectiveness of fluoride dentifrices in preventing enamel erosion. A total of 120 sound intact human premolar teeth which were extracted for orthodontic treatment were selected for the study. A 3 × 3 mm window section was positioned in the middle of the coronal surface of the tooth in order to define the study area. Each sample was placed in a solution of 1% citric acid (pH 3.5) for 10 minutes in order to produce an eroded surface. All samples were divided into two main groups (60 samples each) as follows: Group A for sodium fluoride dentifrices and group B for stannous fluoride dentifrices, again it is subdivided into: CHX: Chlohex ADS®, EO: Listerine®, CPC: Colgate® Plax (20 samples in each subgroup). After that, samples underwent the pH cycling model for 5 days. Samples were examined for surface loss using a scanning electron microscope. In sodium fluoride dentifrices group, before intervention, the surface loss was 3.12 ± 1.03 in CHX group, 3.08 ± 1.20 in EO group, and 3.09 ± 0.96 in CPC group. After intervention, the less surface loss found with CHX group (2.18 ± 0.84), followed by CPC (2.34 ± 0.74) and EO group (2.46 ± 0.97). In stannous fluoride dentifrices group, before intervention, the surface loss in CHX group was 3.26 ± 1.19, in EO group, it was 3.18 ± 1.31, and in CPC group, it was 3.22 ± 1.06. After intervention, the less surface loss found with CHX: group (1.90 ± 0.54), followed by CPC (2.24 ± 0.28) and EO group (2.38 ± 0.20). The present study concluded that the fluoride dentifrices' preventive effects against tooth surface loss were unaffected by a different mouthwashes with varying compositions and major constituents. In terms of erosion, fluoridated toothpaste containing stannous fluoride was found to provide better surface loss protection than sodium fluoride. Primary prevention and the eradication of contributing causes are the greatest strategies for preventing erosion. Simultaneously, antibacterial agent in the mouthwashes may help in enhancing the effect of fluoride in the enamel, owing to their high affinity for teeth structures. Therefore, in addition to cause-related treatment, further efforts to reduce tooth tissue loss are also necessary.

The Effect of Microwave Irradiation and Some Denture Cleansers on The Bond Strength of Soft Liner to CAD/CAM-Milled Acrylic Resin

Disinfection of dentures and denture liners was desired for cross-contamination prevention and improved safety. Nonetheless, it has been discovered that these procedures impact the physical and mechanical features of denture liners.To assess the impact of different disinfection procedures on the tensile bond strength of an acrylic-based soft liner with CAD/CAM-based acrylic denture resin. Material and Methods: 25 specimens were collected and randomly divided into five groups (sodium hypochlorite, chlorohexidine, cleansing tablet, microwave, and control groups), following the daily disinfection protocol, the samples were stored at room temperature (23±2°C) in distilled water. After 30 days, the tensile bond strength was determined using universal testing equipment (Gester, China). The specimens were subjected to force by the machine at a steady crosshead speed of 5 mm/minute till the failure was recorded. The data were analyzed using statistics software (SPSS). Results: Showed that the control group had a higher mean value for bond strength, whereas the chlorhexidine group had a lower value. There was no significant difference between the control and cleansing tablet groups. However, they were significantly different from the microwave, CHX, and NaOCl groups. The NaOCl soft liner group is significantly different from all the other groups. No significant difference is found between microwave and CHX disinfected liner groups. Conclusion: The tensile bond strength of all disinfected soft liners decreased as compared with the control, which was not significant with the protefix tab but significant with the NaOCl, CHX, and microwave groups.

Lowering the percolation threshold when filling polystyrene with surface-functionalized carbon nanohorns

Carbon nanohorns (CNHs) are highly porous material composed of spherical aggregates of short carbon tubes with closed ends. Given their significant potential for a variety of applications, including electromagnetic shielding, it is important to tune the morphology and surface functionality of CNHs. In this study, CNHs functionalized with –CHx groups were synthesized by arc discharge of a graphite rod with the addition of toluene vapor. The resulting material was used as a filler for polystyrene composites, whose electromagnetic properties were studied over the frequency range of 1 kHz–4 GHz. Our research showed that functionalization increases the electrostatic association of CNHs, thereby facilitating the formation of conduction paths. As a result, polymer composites containing functionalized CNHs exhibit improved electromagnetic response and lower electrical percolation threshold. The insights gathered from this study provide crucial information on the relation between charge transport and polarization phenomena, the structure of CNHs, their surface state, and their arrangement in the polymer matrix. This information could potentially aid in the further development of this exceptional material.

Biological properties of experimental dental alginate modified for self-disinfection using green nanotechnology

ObjectivesDisinfection of alginate impression materials is a mandatory step to prevent cross-infection in dental clinics. However, alginate disinfection methods are time-consuming and exert a negative impact on accuracy and mechanical properties. Thus, this study aimed to prepare disinfecting agents (CHX and AgNO3) and silver nanoparticles reduced by a natural plant extract to produce a self-disinfecting dental alginate.MethodsConventional alginate impression material was used in this study. Silver nitrate (0.2% AgNO3 group) and chlorohexidine (0.2% CHX group) solutions were prepared using distilled water, and these solutions were later employed for alginate preparation. Moreover, a 90% aqueous plant extract was prepared from Boswellia sacra (BS) oleoresin and used to reduce silver nitrate to form silver nanoparticles that were incorporated in the dental alginate preparation (BS+AgNPs group). The plant extract was characterized by gas chromatography/mass spectrometry (GC/MS) analysis while green-synthesized silver nanoparticles (AgNPs) were characterized by UV-visible (UV–vis) spectroscopy and scanning electron microscopy (SEM). An agar disc diffusion assay was used to test the antimicrobial activity against Candida albicans, Streptococcus mutans, Escherichia coli, methicillin-resistant and susceptible Staphylococcus aureus strains, and Micrococcus luteus. Agar plates were incubated at 37 ± 1 °C for 24 h to allow microbial growth. Diameters of the circular inhibition zones formed around each specimen were measured digitally by using ImageJ software.ResultsChemical analysis of the plant extract revealed the presence of 41 volatile and semi-volatile active compounds. UV–Vis spectrophotometry, SEM, and EDX confirmed the formation of spherical silver nanoparticles using the BS extract. CHX, AgNO3, and the BS+AgNPs modified groups showed significantly larger inhibition zones than the control group against all tested strains. BS+AgNPs and CHX groups showed comparable efficacy against all tested strains except for Staphylococcus aureus, where the CHX-modified alginate had a significantly higher effect.Conclusions and clinical relevanceCHX, silver nitrate, and biosynthesized silver nanoparticles could be promising inexpensive potential candidates for the preparation of a self-disinfecting alginate impression material without affecting its performance. Green synthesis of metal nanoparticles using Boswellia sacra extract could be a very safe, efficient, and nontoxic way with the additional advantage of a synergistic action between metal ions and the phytotherapeutic agents of the plant extract.

In vitro efficacy of synthetic lawsone derivative disinfectant solution on removing dual-species biofilms and effect on acrylic denture surface properties

Candida albicans (C. albicans) and Streptococcus mutans (S. mutans) biofilms involve in denture stomatitis. This study compared compound 1 to 2% chlorhexidine gluconate (CHX), Polident, and distilled water (DW) in biofilms reduction and effect on polymethylmethacrylate acrylic (PMMA) properties. The structure of lawsone (naphthoquinone derivative) was modified by the addition of an alkylnyloxy group to yield compound 1. Dual-species biofilms of C. albicans and S. mutans were developed on PMMA discs. The colony-forming unit count measured the number of residual biofilm cells after exposure to the test agents. PMMA discs were examined for color stability, surface roughness, hardness, and chemical structure after 28 days. At 3 min, compound 1 was less effective than CHX in reducing C. albicans (p = 0.004) and S. mutans (p = 0.034) but more effective than Polident in reducing C. albicans (p = 0.001). At 15 min, no viable cells were detectable for compound 1 and its effectiveness was comparable to CHX (p = 0.365). SEM showed fungal cell surface damages in CHX, compound 1 and Polident groups. Only color change was affected by time (p < 0.001) and type of test agent (p = 0.008), and only CHX reached a clinical perception level. Compound 1 is a promising agent for removing biofilm from the PMMA surface without substantially degrading surface properties.

Bonding Protocols to Reverse the Bond Strength of a Universal Adhesive to Hemostatic Agent-contaminated Dentin.

To evaluate the effect of different bonding protocols on the microtensile bond strength (μTBS) of a universal adhesive to dentin contaminated with a hemostatic agent. Ninety-five extracted premolars were used in this study. For the μTBS test, 80 teeth were cut to expose mid-coronal dentin and randomly divided into two groups (uncontaminated dentin and hemostatic agent-contaminated dentin). Each group was further divided into five subgroups (n=8/group): 1) SE: no additional treatment, 2) ER: etching with 32% phosphoric acid, 3) CHX: rinsing with 0.2% chlorhexidine, 4) EDTA: rinsing with 17% EDTA, and 5) T40: application of universal adhesive for 40 seconds. A universal adhesive was applied followed by resin composite build-up. μTBS test was performed after 24 hours of water storage. Two-way analysis of variance (ANOVA) was calculated followed by the Duncan testing (α=0.05). The failure mode was analyzed using light microscopy. Additional teeth were prepared for energy-dispersive X-ray (EDX) analysis (n=1/group) and resin-dentin interface observation (n=2/group) using scanning electron microscopy. Adverse effects of hemostatic agent contamination on the bonding performance of a universal adhesive was found in the SE, CHX, and T40 groups (p<0.05). Fewer and shorter resin tags were observed in the SE, CHX, and T40 groups. A higher percentage of adhesive failure and mixed failure was found in contaminated dentin. All bonding protocols revealed lower amounts of Al and Cl after dentin contamination, except for the SE group. Hemostatic agent contamination adversely affected dentin bond strength. However, this bond strength could be reversed using the etch-and-rinse technique or rinsing with EDTA prior to adhesive application.

Evaluation of The Interaction Between Alternative Endodontic Irrigation Solutions

Statement of the problem: For successful endodontic treatment, mechanical cleaning and chemical irrigation can be used together. Since the-re is not yet a single solution sufficient for both root canal cleaning alone, combined use of irrigants is recommended for the synergistic effect. Poly-hexanide (PHMB), boric acid, phytic acid, peracetic acid, and hypochlorous acid are relatively new alternative endodontic irrigation solutions and there are no studies in the literature on the combined use of alternative solutions. Objective: This study aimed to evaluate the interactions that would result from applying PHMB as a substitute for CHX following alternative in-termediate irrigation solutions that might be utili-zed with NaOCl. Materials &amp; Methods: Eight microtubes were used for this study. 0.5ml of 5%NaOCl was placed in each microtube first, the microtubes were divided into two groups as the final product CHX and Polyhexanide, and the two groups were divided into four groups with different irrigants in themselves. The study was conducted at room temperature and the images of the mixtures were photographed at 1 min, 10 min, 20 min, 30 min, and 1 hour. Groups; G1: NaOCl+ 1%Phytic acid +0.1%Polyhexanide, G2: NaOCl+ 0.02%Hypochlorous acid +0.1%Polyhexanide, G3: NaOCl+ 2% Peracetic acid +0.1%Polyhexanide, G4: NaOCl+ 5% Boric acid +0.1%Polyhexanide, G5: NaOCl+ Phytic acid+ 2%CHX, G6: NaOCl+ 0.02%Hypochlorous acid +2%CHX, G7: NaOCl+ 2% Peracetic acid+2%CHX, G8: NaOCl+ 5% Boric acid + 2%CHX. Results: White or brown precipitates occurred as soon as the soluti-ons were applied to all of the CHX groups; milky-white precipitate was only seen in the Polyhexanide group's Phytic acid-added group. After 5 minutes, air bubbles were seen in the Polyhexanide group that had Peracetic acid ad-ded, whereas the CHX group had an increase in brown precipitates. Conclusions: Considering the current research conditions, In clinical practice, the administration of Polyhexanite as the last irrigant and the com-bination of NaOCl with boric acid or hypochlorous acid can be advised.

Efficacy of adjunct photodynamic therapy on Candida growth and oral health quality of life in denture stomatitis patients with type 2 diabetes mellitus wearing implant-retained overdentures: A randomized clinical study

AimThe aim of the present clinical trial was to study the efficacy of combined miconazole and PDT in the improvement of quality of life and levels of Candida species in chronic hyperglycemic patients with denture stomatitis (DS). MethodsOne hundred patients were randomly divided into five groups; 20 each in the miconazole, PDT, miconazole+ PDT, CHX and distilled water groups. Methylene blue mediated irradiation was conducted using 600 nm diode laser with power, energy density and radiance as 100 mW, 3527 mW/cm2 and 9 J, respectively. Patients were advised to apply 2.5 ml of 2% topical miconazole four times a day. The existence of Candida spp. was detected by means of microbiological culture technique. Candida colony counts from the palates and dentures surfaces, quantified as colony forming unit (CFU)/mL were evaluated at baseline, end of 14 days, 28 days and 60 days. Oral health related quality of life was assessed with the help of a questionnaire. ResultsThe quality of life showed significant improvement in the group where combination treatment was executed. The overall CFU/mL values were greater in the dentures in comparison to those from the palates of the patients of all the five groups. During all time periods of the study, the CFU/mL values obtained from combination treatment group showed significant differences. Candida albicans was the most predominant yeast. ConclusionThis study showed the effectiveness of methylene blue- PDT in combination with miconazole in improving oral health related quality of life and significantly reducing Candida CFU counts to resolve palatal inflammation in diabetic individuals with implant-supported complete dentures.

Mechanical and Physical Properties of an Experimental Chemically and Green-Nano Improved Dental Alginate after Proven Antimicrobial Potentials.

Impression materials could be a source of cross-contamination due to the presence of microorganisms from blood and saliva inside the oral cavity. Nevertheless, routinely performed post-setting disinfection could compromise the dimensional accuracy and other mechanical properties of alginates. Thus, this study aimed to evaluate detail reproduction, dimensional accuracy, tear strength, and elastic recovery of new experimentally prepared self-disinfecting dental alginates. Two antimicrobial-modified dental alginate groups were prepared by mixing alginate powder with 0.2% silver nitrate (AgNO3 group) and a 0.2% chlorohexidine solution (CHX group) instead of pure water. Moreover, a third modified group was examined by the extraction of Boswellia sacra (BS) oleoresin using water. The extract was used to reduce silver nitrate to form silver nanoparticles (AgNPs), and the mixture was used as well in dental alginate preparation (BS + AgNP group). Dimensional accuracy and detail reproduction were examined as per the ISO 1563 standard guidelines. Specimens were prepared using a metallic mold engraved with three parallel vertical lines 20, 50, and 75 µm wide. Detail reproduction was evaluated by checking the reproducibility of the 50 µm line using a light microscope. Dimensional accuracy was assessed by measuring the change in length between defined reference points. Elastic recovery was measured according to ISO 1563:1990, in which specimens were gradually loaded and then the load was released to allow for recovery from the deformation. Tear strength was evaluated using a material testing machine until failure at a crosshead speed of 500 mm/min. The recorded dimensional changes between all tested groups were insignificantly different and within the reported acceptable values (between 0.037-0.067 mm). For tear strength, there were statistically significant differences between all tested groups. Groups modified with CHX (1.17 ± 0.26 N/mm) and BS + AgNPs (1.11 ± 0.24 N/mm) showed higher tear strength values compared to the control (0.86 ± 0.23 N/mm) but were insignificant from AgNO3 (0.94 ± 0.17 N/mm). All tested groups showed elastic recovery values that met both the ISO standard and ADA specifications for elastic impression materials and tear strength values within the acceptable documented ranges. The CHX, silver nitrate, and green-synthesized silver nanoparticles could be promising, inexpensive alternatives for the preparation of a self-disinfecting alginate impression material without affecting its performance. Green synthesis of metal nanoparticles could be a very safe, efficient, and nontoxic method, with the advantage of having a synergistic effect between metal ions and active chemical constituents of plant extracts.