BACKGROUND AND OBJECTIVE

Orthodontic brackets predispose dental biofilm accumulation causing caries and gingivitis. Chlorhexidine is an adjunct to mechanical plaque removal, but has side-effects (tooth staining, bacterial resistance) due to long term use. This study tested the efficacy of Photodynamic Therapy, which produces reactive oxygen species, to reduce Streptococcus mutans in dental biofilm on orthodontic brackets.

A 5-day S. mutans biofilm was grown on forty enamel-bracket specimens. Thirty-nine specimens were randomized to three treatment groups: A. Distilled Water; B. 0.12% Chlorhexidine (CHX); C. Photodynamic Therapy (PDT) using Toluidine Blue O (TBO) as a photosensitizer, activated by red LED (630nm). After treatment, one random specimen from each group was viewed under Environmental Scanning Electron Microscopy (ESEM); the other 12 specimens, biofilms were collected, weighed, and cultured onto BHI agar plates to determine the number of CFU/mg. For baseline evaluation, one clean and one untreated specimens were preserved for ESEM.

Based on Tukey HSD test, group A had the most S. mutans (37.0573 CFU/mg) and was significantly different (p < 0.05) from groups B (0.1712 CFU/mg) and C (1.1193 CFU/mg), where both showed less bacteria than group A. The statistical difference between groups B and C was insignificant. ESEM images showed specimen A covered with more abundant and denser S. mutans biofilm than specimens B and C, with almost similar morphology showing sparse, less dense, and disintegrated biofilm with unclear cellular walls and presence of amorphous masses.

Both Photodynamic Therapy and 0.12% Chlorhexidine showed a significant reduction of S. mutans in dental biofilm on orthodontic brackets. However, there is no significant difference between them in reducing S. mutans CFU/mg. Photodynamic therapy could be an alternative adjunctive tool to mechanical removal of plaque adhered to orthodontic brackets.

BACKGROUND AND OBJECTIVE

Orthodontic brackets predispose dental biofilm accumulation causing caries and gingivitis. Chlorhexidine is an adjunct to mechanical plaque removal, but has side-effects (tooth staining, bacterial resistance) due to long term use. This study tested the efficacy of Photodynamic Therapy, which produces reactive oxygen species, to reduce Streptococcus mutans in dental biofilm on orthodontic brackets.

A 5-day S. mutans biofilm was grown on forty enamel-bracket specimens. Thirty-nine specimens were randomized to three treatment groups: A. Distilled Water; B. 0.12% Chlorhexidine (CHX); C. Photodynamic Therapy (PDT) using Toluidine Blue O (TBO) as a photosensitizer, activated by red LED (630nm). After treatment, one random specimen from each group was viewed under Environmental Scanning Electron Microscopy (ESEM); the other 12 specimens, biofilms were collected, weighed, and cultured onto BHI agar plates to determine the number of CFU/mg. For baseline evaluation, one clean and one untreated specimens were preserved for ESEM.

Based on Tukey HSD test, group A had the most S. mutans (37.0573 CFU/mg) and was significantly different (pCONCLUSION

Both Photodynamic Therapy and 0.12% Chlorhexidine showed a significant reduction of S. mutans in dental biofilm on orthodontic brackets. However, there is no significant difference between them in reducing S. mutans CFU/mg. Photodynamic therapy could be an alternative adjunctive tool to mechanical removal of plaque adhered to orthodontic brackets.

OBJECTIVES: The integrated endoplasmic reticulum stress inhibitor (ISRIB) is a selective inhibitor of the protein kinase R-like endoplasmic reticulum kinase (PERK) signaling pathway within endoplasmic reticulum stress (ERS) and can improve spatial and working memory in aged mice. Although ERS and oxidative stress are tightly interconnected, it remains unclear whether ISRIB alleviates cognitive impairment by restoring the balance between ERS and oxidative stress. This study aims to investigate the effects and mechanisms of ISRIB on lipopolysaccharide (LPS)-induced cognitive impairment in mice. METHODS: Eight-week-old male ICR mice were randomly divided into 3 groups: Normal saline (NS) group, LPS group, and ISRIB+LPS group. NS and LPS groups received daily intraperitoneal injections of normal saline for 7 days; on day 7, LPS group mice received intraperitoneal LPS (0.83 mg/kg) to establish a cognitive impairment model. ISRIB+LPS group received ISRIB (0.25 mg/kg) intraperitoneally for 7 days, with LPS injected 30 minutes after ISRIB on day 7. Cognitive ability was evaluated by the novel place recognition test (NPRT). Real-time fluorogenic quantitative PCR (RT-qPCR) was used to detect changes in nitric oxide synthase (NOS), superoxide dismutase-1 (SOD-1), and catalase (CAT) gene expression in the hippocampus and prefrontal cortex. Oxidative stress markers malondialdehyde (MDA), glutathione (GSH), and oxidized glutathione (GSSG), were measured in hippocampal and prefrontal cortex tissues. RESULTS: Compared with the NS group, mice in LPS group showed a significant reduction in novel place recognition ratio, upregulation of hippocampal NOS-1 and NOS-2 mRNA, downregulation of SOD-1 and CAT mRNA, increased MDA and GSSG, decreased GSH, and reduced GSH/GSSG ratio (all P<0.05). Compared with the LPS group, mice in ISRIB+LPS group exhibited significantly improved novel place recognition, downregulated NOS-1 and NOS-2 mRNA, upregulated SOD-1 and CAT mRNA, decreased MDA and GSSG, increased GSH, and an elevated GSH/GSSG ratio in the hippocampus (all P<0.05). No significant changes were observed in the prefrontal cortex. CONCLUSIONS ISRIB improves LPS-induced cognitive impairment in mice by restoring the oxidative/antioxidant balance in the hippocampus.
Animals ; Lipopolysaccharides ; Male ; Mice, Inbred ICR ; Cognitive Dysfunction/drug therapy* ; Mice ; Oxidative Stress/drug effects* ; Endoplasmic Reticulum Stress/drug effects* ; Hippocampus/drug effects* ; Nitric Oxide Synthase Type II/genetics* ; Guanidines/pharmacology* ; eIF-2 Kinase/antagonists & inhibitors* ; Signal Transduction/drug effects* ; Superoxide Dismutase/metabolism*

OBJECTIVES: This study aimed to evaluate the therapeutic effect of 1% povidone-iodine mouthwash combined with scaling and root planing in patients with stage Ⅰ/Ⅱ class A/B periodontitis, and to provide a basis for the clinical application of povidone-iodine mouthwash. METHODS: Seventy-five subjects were included in this trial and randomly divided into three groups. After full-mouth ultrasonic supragingival cleansing, scaling and root planing, the placebo group was treated with sodium chloride injection (NaCl group), the control group was treated with compound chlorhexidine mouthwash (CHX group), and the experimental group was treated with 1% povidone-iodine mouthwash (PVP-I group), and rinsed their mouths for 1 week, respectively. Subjects were tested at 1, 4, and 12 weeks after dosing for clinical indicators, microbial composition of supragingival plaque, gingival crevicular fluid inflammatory marker levels, and patient-reported outcomes. RESULTS: Sixty-three subjects completed the follow-up. After treatment, the clinical indicators, microbial indicators, and inflammatory indicators were all significantly improved (P<0.05). Comparisons among the groups showed that one week after treatment, the bleeding index and plaque index of the CHX group and the PVP-I group were lower than those of the NaCl group, and the plaque index of the CHX group was lower than that of the PVP-I group (P<0.05). There were no statistically significant differences in the other clinical indicators among the groups (P>0.05). Twelve weeks after treatment, the Shannon index of the CHX group was lower than that of the NaCl group (P<0.05), and there were no statistically significant differences in the other microbial indicators among the groups (P>0.05). Twelve weeks after treatment, the interleukin-10 concentration of the CHX group was higher than that of the NaCl group (P<0.05), and there were no statistically significant differences in the other inflammatory indicators among the groups (P>0.05). The PVP-I group had the highest scores in terms of taste and oral odor. There was no obvious staining on the tooth surfaces and mucosa in all three groups. CONCLUSIONS 1% PVP-I mouthwash combined with scaling and root planing can effectively reduce gingival inflammation and dental plaque, improve clinical symptoms in the short term. While its efficacy is not significantly inferior to that of chlorhexidine, PVP-I mouthwash is more acceptable to patients than chlorhexidine.
Humans ; Povidone-Iodine/administration & dosage* ; Mouthwashes/therapeutic use* ; Dental Scaling ; Root Planing ; Periodontitis/microbiology* ; Gingival Crevicular Fluid/chemistry* ; Anti-Infective Agents, Local/therapeutic use* ; Female ; Male ; Chlorhexidine/therapeutic use* ; Dental Plaque/microbiology* ; Middle Aged ; Adult

Severe allergic reactions to hydrogen peroxide solution and compound chlorhexidine gargle are rare, and most medical professionals have limited understanding of such cases. This article reports a case of anaphylactic shock in a patient with a periodontal abscess following oral flushing with hydrogen peroxide and compound chlorhexidine gargle. Drawing on domestic and international literature, it provides a reference for the emergency management of serious adverse reactions caused by these agents.
Humans ; Anaphylaxis/chemically induced* ; Anti-Infective Agents, Local/adverse effects* ; Chlorhexidine/adverse effects* ; Hydrogen Peroxide/adverse effects* ; Mouthwashes/adverse effects*

OBJECTIVE: To investigate the effect of improved nursing strategy on prognosis of older immunosuppressed patients with pneumonia and sepsis. METHODS: A prospective study was conducted. The older immunosuppressed patients with pneumonia and sepsis admitted to the department of intensive care medicine and emergency intensive care unit (ICU) of Peking Union Medical College Hospital from January 2017 to July 2022 were enrolled. In the first stage (from January 2017 to December 2019), patients received the original nursing strategy (original nursing strategy group), including: (1) nurses were randomly assigned; (2) routine terminal cleaning; (3) ICU environmental cleaning twice a day; (4) oral care was performed with chlorhexidine twice a day; (5) original lung physiotherapy [head of bed elevated at 30 degree angle-45 degree angle, maintaining a Richmond agitation-sedation scale (RASS) -2 to 1, sputum aspiration as needed]. After 1 month of learning and training of the modified nursing treatment strategy for nurses and related medical staff, the patients in the second stage (from February 2020 to July 2022) received the improved nursing strategy (improved nursing strategy group). The improved nursing strategy improved the hospital infection prevention and control strategy and lung physical therapy strategy on the basis of the original nursing strategy, including: (1) nurses were fixed assigned; (2) patients were placed in a private room; (3) enhanced terminal cleaning; (4) ICU environmental cleaning four times a day; (5) education and training in hand hygiene among health care workers was improved; (6) bathing with 2% chlorhexidinegluconate was performed once daily; (7) oral care with a combination of chlorhexidine and colistin was provided every 6 hours; (8) surveillance of colonization was conducted; (9) improved lung physiotherapy (on the basis of the original lung physiotherapy, delirium score was assessed to guide early mobilization of the patients; airway drainage was enhanced, the degree of airway humidification was adjusted according to the sputum properties, achieving sputum viscosity grade II; lung ultrasound was also used for lung assessment, and patients with atelectasis were placed in high lateral position and received the lung recruitment maneuver). Baseline patient information were collected, including gender, age, underlying diseases, source of admission, disease severity scores, vital signs, ventilatory parameters, blood gas analysis, life-sustaining treatments, clinical laboratory evaluation, indicators of infection and inflammation, pathogens and drug therapy. The primary outcome was 28-day mortality, and the secondary outcomes were duration of mechanical ventilation, length of ICU stay, and ICU mortality. Multivariate Logistic regression analysis was used to determine the risk factors for 28-day death in older immunosuppressed patients with pneumonia and sepsis. RESULTS: Finally, 550 patients were enrolled, including 199 patients in the original nursing strategy group and 351 patients in the improved nursing strategy group. No significant differences were found in gender, age, underlying diseases, source of admission, disease severity scores, vital signs, ventilatory parameters, blood gas analysis, life-sustaining treatments, clinical laboratory evaluation, indicators of infection and inflammation, coexisting pathogens or drug therapy between the two groups. Compared with patients in the original nursing strategy group, those in the improved nursing strategy group had significantly fewer duration of mechanical ventilation and length of ICU stay [duration of mechanical ventilation (days): 5 (4, 7) vs. 5 (4, 9), length of ICU stay (days): 11 (6, 17) vs. 12 (6, 23), both P < 0.01], and lower ICU mortality and 28-day mortality [ICU mortality: 23.9% (84/351) vs. 32.7% (65/199), 28-day mortality: 23.1% (81/351) vs. 33.7% (67/199), both P < 0.05]. Multivariate Logistic regression analysis showed that the improved nursing strategy acted as an independent protective factor in 28-day death of older immunosuppressed patients with pneumonia and sepsis [odds ratio (OR) = 0.543, 95% confidence interval (95%CI) was 0.334-0.885, P = 0.014]. CONCLUSIONS Improved nursing strategy shortened the duration of mechanical ventilation and the length of ICU stay, and decreased ICU mortality and 28-day mortality in older immunosuppressed patients with pneumonia and sepsis, significantly improving the short-term prognosis of such patients.
Humans ; Aged ; Prospective Studies ; Chlorhexidine/therapeutic use* ; Intensive Care Units ; Pneumonia ; Prognosis ; Sepsis/therapy* ; Inflammation

OBJECTIVE: To construct a model of Enterococcus faecalis (E. faecalis) infection in dentinal tubules by gradient centrifugation and to evaluate the antibacterial effect of low-temperature plasma on E. faecalis in dentinal tubules. METHODS: Standard dentin blocks of 4 mm×4 mm×2 mm size were prepared from single root canal isolated teeth without caries, placed in the E. faecalis bacterial solution, centrifuged in gradient and incubated for 24 h to establish the model of dentinal tubule infection with E. faecalis. The twenty dentin blocks of were divided into five groups, low-temperature plasma jet treatment for 0, 5 and 10 min, calcium hydroxide paste sealing for 7 d and 2% chlorhexidine gel sealing for 7 d. Scanning electron microscopy and confocal laser scanning microscope were used to assess the infection in the dentinal tubules and the antibacterial effect of low-temperature plasma. RESULTS: The results of scanning electron microscopy and confocal laser scanning microscopy showed that after 24 h of incubation by gradient centrifugation, E. faecalis could fully enter the dentinal tubules to a depth of more than 600μm indicating that this method was time-saving and efficient and could successfully construct a model of E. faecalis infection in dentinal tubules. Low-temperature plasma could enter the dentinal tubules and play a role, the structure of E. faecalis was still intact after 5 min of low-temperature plasma treatment, with no obvious damage, and after 10 min of low-temperature plasma treatment, the surface morphology of E. faecalis was crumpled and deformed, the cell wall was seriously collapsed, and the normal physiological morphology was damaged indicating that the majority of E. faecalis was killed in the dentinal tubules. The antibacterial effect of low-temperature plasma treatment for 10 min exceeded that of the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d. These two chemicals had difficulty entering deep into the dentinal tubules, and therefore only had a few of antibacterial effect on the bacterial biofilm on the root canal wall, and there was also no significant damage to the E. faecalis bacterial structure. CONCLUSION Gradient centrifugation could establish the model of E. faecalis dentin infection successfully. Low-temperature plasma treatment for 10 min could kill E. faecalis in dentinal tubules effectively, which is superior to the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d.
Chlorhexidine/pharmacology* ; Calcium Hydroxide/pharmacology* ; Enterococcus faecalis/physiology* ; Temperature ; Dentin ; Biofilms ; Anti-Bacterial Agents/pharmacology* ; Root Canal Irrigants/pharmacology* ; Dental Pulp Cavity

To review and investigate the diagnosis results of local anesthetics (LA) allergy and improve the understanding of LA allergy in clinician. From March 2017 to February 2022, a total of 24 patients were investigated in Allergy Center of West China Hospital,Sichuan University on suspicion of LA allergy. Clinical data and results of skin tests and drug provocation tests (DPT) with the suspected drugs were retrospectively evaluated. The value of standardized diagnostic protocol in the LA allergy were analyzed. The results showed that 24 patients (3 men/21 women) were included with age range from 20 to 74 years. Three cases (12.5%) were positive in previous LA skin tests and proved to be tolerated through standardized tests. Twenty-one patients were initially diagnosed as "LA allergy" because of adverse reactions after previous use of LA, including 20 cases of immediate-type reaction and 1 case of delayed-type reaction. Three cases were considered LA allergy through standardized diagnosis approaches, including skin tests and DPT. One patient was diagnosed with anaphylaxis caused by chlorhexidine. Of the remaining 17 patients, 7 were considered as psychosomatic reactions (29.1%), 3 of sympathetic nervous system conditions (12.5%), 1 of spontaneous urticaria (4.2%), 2 of vasovagal syncope (8.3%), drug side effects (8.3%), skin irritation (8.3%), respectively. In conclusion, true allergic reactions to LA are rare. Through standardized skin tests and DPT, allergy can be ruled out in the vast majority of patients who complain of "LA allergy". For patients who are highly suspected of LA inducing anaphylaxis, other local anesthetics that can be used as safe alternatives should be determined by diagnostic tests according to future needs.
Male ; Humans ; Female ; Young Adult ; Adult ; Middle Aged ; Aged ; Anesthetics, Local/adverse effects* ; Anaphylaxis/diagnosis* ; Retrospective Studies ; Drug-Related Side Effects and Adverse Reactions ; Chlorhexidine

To review and investigate the diagnosis results of local anesthetics (LA) allergy and improve the understanding of LA allergy in clinician. From March 2017 to February 2022, a total of 24 patients were investigated in Allergy Center of West China Hospital,Sichuan University on suspicion of LA allergy. Clinical data and results of skin tests and drug provocation tests (DPT) with the suspected drugs were retrospectively evaluated. The value of standardized diagnostic protocol in the LA allergy were analyzed. The results showed that 24 patients (3 men/21 women) were included with age range from 20 to 74 years. Three cases (12.5%) were positive in previous LA skin tests and proved to be tolerated through standardized tests. Twenty-one patients were initially diagnosed as "LA allergy" because of adverse reactions after previous use of LA, including 20 cases of immediate-type reaction and 1 case of delayed-type reaction. Three cases were considered LA allergy through standardized diagnosis approaches, including skin tests and DPT. One patient was diagnosed with anaphylaxis caused by chlorhexidine. Of the remaining 17 patients, 7 were considered as psychosomatic reactions (29.1%), 3 of sympathetic nervous system conditions (12.5%), 1 of spontaneous urticaria (4.2%), 2 of vasovagal syncope (8.3%), drug side effects (8.3%), skin irritation (8.3%), respectively. In conclusion, true allergic reactions to LA are rare. Through standardized skin tests and DPT, allergy can be ruled out in the vast majority of patients who complain of "LA allergy". For patients who are highly suspected of LA inducing anaphylaxis, other local anesthetics that can be used as safe alternatives should be determined by diagnostic tests according to future needs.
Male ; Humans ; Female ; Young Adult ; Adult ; Middle Aged ; Aged ; Anesthetics, Local/adverse effects* ; Anaphylaxis/diagnosis* ; Retrospective Studies ; Drug-Related Side Effects and Adverse Reactions ; Chlorhexidine

OBJECTIVE: To investigate the changes of skin temperature, blood infusion and inflammatory cytokines of cutaneous tissue in the sensitized area of colitis model rats, as well as the relationship between sensory and sympathetic nerves and the formation of sensitized area, and to initially reveal the partial physical-chemical characteristics of the sensitized area in the colitis model rats. METHODS: Thirty-five male SD rats were randomly divided into a control group (n=10), a model group (n=18) and a guanethidine group (n=7). 5% dextran sulfate sodium (DSS) was adopted for 6-day free drinking to establish colitis model in the model group and the guanethidine group. On day 6 and 7, in the guanethidine group, guanethidine solution (30 mg/kg) was injected intraperitoneally for sympathetic block. On day 7, after injection of evans blue (EB) solution, the EB extravasation areas on the body surface were observed to investigate the distribution and physical-chemical characteristics of the sensitized area. The control area was set up, 0.5 cm away from the sensitized area, and with the same nerve segment innervation. Disease activity index (DAI) score of rats was compared between the normal group and the model group, and the morphological changes in the colon tissue were investigated with HE method. Using infrared thermal imaging technology and laser speckle flow imaging technology, skin temperature and blood infusion were determined in the sensitized area and the control area of the rats in the model group. Immunofluorescence technique was adopted to observe the expression levels of the positive nerve fibers of substance P (SP), calcitonin gene-related peptide (CGRP) and tyrosine hydroxylase (TH), and the correlation with blood vessels; as well as the expression levels of SP positive nerve fibers/tryptase⁺ mast cells, and tryptase⁺ mast cells/5-hydroxytryptamine (5-HT) in skin tissue in the sensitized area and the control area of the rats in the model group. MSD multi-level factorial method and ELISA were applied to determine the contents of pro-inflammatory and anti-inflammatory cytokines (e.g. TNF-α, IL-1β, IL-6, IL-4 and IL-10) and anti-inflammatory substance corticosterone (CORT). RESULTS: Sensitization occurred at the T₁₂-S₁ segments of the colitis model rats, especially at L₂-L₅ segments. Compared with the normal group, DAI score was increased in the rats of the model group (P<0.05), and the colonic mucosal damage was obvious, with the epithelial cells disordered, even disappeared, crypt destructed, submucosal edema and a large number of inflammatory cells infiltrated. In comparison with the control area, the skin temperature and blood infusion were increased in the sensitized area of the model group (P<0.05, P<0.01); as well as the expression levels of the positive nerve fibers of SP, CGRP and TH of skin tissue (P<0.05), which was specially distributed in peripheral vessels, the expression levels of SP positive nerve fibers/tryptase⁺ mast cells, and tryptase⁺ mast cells/5-HT of the skin tissue were all expanded (P<0.05) in the sensitized area of the model group. Compared with the model group, the number of sensitized areas was reduced in the guanethidine group (P<0.05). In comparison with the control area of the model group, in the sensitized area, the contents of pro-inflammatory cytokines, e.g. TNF-α, IL-1β and IL-6, and the anti-inflammatory substance CORT of skin tissue were all increased (P<0.05); and the contents of IL-6 and TNF-α were negatively correlated with CORT (P<0.05). CONCLUSION The sensitized areas on the body surface of colitis rats are mainly distributed in the L₂-L₅ segments. Sensory and sympathetic nerves are involved in the acupoint sensitization, and the sensitized areas may have the dynamic changes in pro-inflammatory and anti-inflammatory substances.
Animals ; Anti-Inflammatory Agents ; Calcitonin Gene-Related Peptide/metabolism* ; Colitis/metabolism* ; Cytokines/metabolism* ; Guanethidine ; Interleukin-6 ; Male ; Rats ; Rats, Sprague-Dawley ; Serotonin ; Skin Temperature ; Substance P/genetics* ; Tryptases ; Tumor Necrosis Factor-alpha