Influence of systemic antibiotic therapy on the development and progression of induced apical periodontitis in Wistar rats.

The aim of this study was to investigate the influence of systemic antibiotic therapy on the development and progression of induced apical periodontitis (AP) in Wistar rats. Fifty-six rats were submitted to pulp exposure of the lower left first molar for the induction of AP. On the same day, intraperitoneal antibiotic therapy was administered once a day, for 15 days, until euthanasia. The groups were formed according to the different treatments (n = 8): C-control; GEN-treated with gentamicin (10 mg/Kg); AC-treated with amoxicillin (100 mg/Kg); MZ-treated with metronidazole (40 mg/Kg); AMP-treated with ampicillin (100 mg/Kg); AMC group-treated with amoxicillin + clavulanic acid (100 mg/kg); CLI-treated with clindamycin (60 mg/kg). After euthanasia, the jaws were collected and processed for (1) histological and histometric analysis using hematoxylin and eosin staining, (2) analysis of collagen fibers using Picrosirius Red staining and (3) bacteriological analysis using Brown-Brenn staining. The data were analyzed statistically (p < 0.05). AP induction was confirmed in all groups. The AMC group had the lower intensity of inflammatory infiltrate (p = 0.028) and less periapical bone resorption compared to control (p = 0.006). Regarding collagen maturation, PSR staining revealed a predominance of mature collagen fibers in all groups. The AC and AMC groups had the lower amount of mature fibers and the highest amount of immature fibers, compared to all other groups (p < 0.001). All groups showed bacterial contamination; however, the AC and AMC groups showed a lower extent of bacterial contamination compared to the control (p < 0.001). It can be concluded that systemic antibiotic therapy influences the development and progression of induced AP.

Influence of photoactivation on tissue response to different dyes used in photodynamic therapy and laser ablation therapy.

Laser ablation therapy (LA) uses Indocyanine Green dye (ICG) which efficiently absorbs laser energy and the increased temperature results in an instantaneous flame that chars tissue and microbes. Photodynamic therapy (PDT) uses different dyes that are activated by light to kill bacteria. This study evaluated the biocompatibility of the dye Curcumin (CUR), Methylene Blue (MB), and Indocyanine Green (ICG) before and after laser activation (ACT). Polyethylene tubes containing one of the dyes were implanted in the subcutaneous tissue of 32 rats (4 tubes per rat) which were divided into 8 groups: C - control (saline solution); C + ACT (Red Laser 660 nm); CUR; CUR + ACT (480 nm blue LED); MB; MB + ACT (Red Laser 660 nm); ICG; ICG + ACT (810 nm Infrared Laser). After 7 and 30 days (n = 8/time), the rats were euthanized and the tubes with the surrounding tissue were removed and processed for histological analysis of inflammation using H&E stain, and collagen fiber maturation using picrosirius red (PSR). A two-way analysis of variance statistical test was applied (p < 0.05). At 7 days, regardless of laser activation, the CUR group showed a greater inflammatory infiltrate compared to the ICG and control groups, and the MB group had a greater inflammation only in relation to the control (p < 0.05). At 30 days, CUR and MB groups showed a greater inflammatory infiltrate than the control (p < 0.05). ICG group was equal to the control in both periods, regardless of the laser activation (p > 0.05). Laser activation induced the proliferation of collagen immature fibers at 7 days, regardless of the dye (p < 0.05). The CUR group showed a lower percentage of immature and mature fibers at 7 days, compared to ICG and control (p < 0.05) and, at 30 days, compared to control (p < 0.05). Regardless of laser activation, the ICG showed the results of collagen maturation closest to the control (p > 0.05). It was concluded that all dyes are biocompatible and that laser activation did not interfere with biocompatibility. In addition, the maturity of collagen was adequate before and after the laser activation. These results demonstrate that the clinical use of dyes is safe even when activated with a laser.

Prevalence of apical periodontitis and non-retention of root-filled teeth in hypertensive patients: Systematic review and meta-analysis.

BACKGROUND: Several studies have suggested a relationship between AP, as well as the loss of root-filled teeth (RFT), and hypertension (HTN). OBJECTIVES: The aims of this systematic review and meta-analysis were to investigate the prevalence of AP, and non-retention of RFT, in hypertensive patients. METHODS: A search was performed in PubMed/MEDLINE, Web of Science, Scopus and EMBASE. The inclusion criteria established were studies published until February 2023, comparing hypertensive subjects with controls, assessing the prevalence of AP and/or providing data on the prevalence of non-retained RFT. Meta-analysis was performed using the RevMan (analyst) tool to determine the pooled prevalence of AP and loss of RFT. Risk of bias was assessed using the Cochrane Risk-of-Bias tool. The quality of evidence was assessed by GRADE. RESULTS: The search strategy identified 454 articles, and only eight met the inclusion criteria. Six studies had analysed the association between AP and HTN and two studies had analysed the association between non-retention of RFT and HTN. Meta-analysis showed and overall OR = 1.71 (95% CI = 0.92-3.16; p = .09) for the prevalence of AP among patients with HTN. The prevalence of non-retention of RFT among patients with HTN has an overall OR = 1.78 (95% CI = 1.60-1.98; p = .000001). The risk of bias in the individual studies was low or moderate, and the quality of the overall evidence has shown a level of certainty very low. DISCUSSION: There is no association between the prevalence of AP and HTN. In addition, hypertensive patients have significantly increased odds of losing RFT. Given the high prevalence of hypertension, it is very common to perform root canal treatments on hypertensive patients. It is imperative to communicate this heightened risk to patients and recommend periodic monitoring of oral health and hypertension, paying special attention to this subset of patients. REGISTRATION: PROSPERO CRD42022302385.

Hyposalivation but not Sjögren's syndrome associated with microbial dysbiosis in women.

Background: Saliva modulates the environment of the oral biofilm through pH buffer, microbial attachment to host surfaces, and nutritional source. The ecology of stress occurs when a physical factor adversely impacts an ecosystem or its biotic components. Therefore, reduced salivary flow can affect oral-host balance. The leading causes of hyposalivation include disease-associated Sjögren's syndrome (SS) and menopausal women as aging-associated. However, little is known about the oral microbiome integrated with sex hormones in hyposalivation. This study aimed to characterize the hyposalivation microbiome caused by aging or disease affecting the salivary glands in women. Methods: We included 50 women older than 40 years of age in any menopausal phase. We collected stimulated saliva from 25 women diagnosed with SS (SS) and 25 without SS (non-SS). The bacterial profile of the patients was obtained by 16S rRNA sequencing. Bioinformatics analysis used machine learning to analyze the cohort's signs, symptoms, and bacterial profile. Salivary estradiol as a sex hormone variation level was determined. Results: We obtained that 79% of the SS group, and 52% of the non-SS group had hyposalivation. We found a negatively correlated Prevotella-age and Rothia-estradiol in the SS group. Highlight, we found that the cause of the hyposalivation in the study did not explain differences in microbial diversity comparing non-SS and SS groups. Therefore, microbial communities found in hyposalivation but not related to systemic conditions suggest that changes in the oral environment might underpin host-microbial balance. Conclusion: The salivary microbiome was similar in women with and without SS. However, hyposalivation showed two distinctive clusters associated with the bacterial population profiles. Our study suggests that local ecological disturbances could drive the change in the microbiome.

Modulatory influence of melatonin on apical periodontitis in Wistar rats fed a high-fat diet.

OBJECTIVE: This study aimed to evaluate the influence of high-fat diet (HFD) and melatonin (MEL) treatment on the progression of inflammation and alveolar bone resorption (ABR) in rats with AP. DESIGN: Forty male Wistar rats were divided into four groups: apical periodontitis (AP), HFDAP, APMEL and HFDAPMEL. The animals were fed an HFD or standard diet for 107 days. On the 7th day, the rats were subjected to AP, and after 70 days, the rats in the MEL groups were treated with MEL for 30 days. Post treatment, the animals were euthanized, and their jaws were retrieved for evaluation of bone resorption, intensity of the inflammatory response, and immunohistochemical analysis including tartrate-resistant acid phosphatase (TRAP) and interleukin-1ß (IL-1ß) levels and tumor necrosis factor (TNF)-α expression. RESULTS: The APMEL group showed reduction in the inflammatory infiltrate and IL-1ß expression relation to HFDAP, while the TNF-α levels did not differ among the groups. The HFDAP group showed an increase in the ABR. MEL reduced the TRAP levels in the APMEL and HFDAPMEL groups. CONCLUSIONS: while MEL could reduce TRAP levels in the APMEL and HFDAPMEL groups, the reduction in the HFDAPMEL group was smaller than that in the APMEL group, demonstrating that the interaction between AP and HFD decreased the anti-resorptive effects of MEL.

Melatonin decreases IRF-3 protein expression in the gastrocnemius muscle, reduces IL-1ß and LPS plasma concentrations, and improves the lipid profile in rats with apical periodontitis fed on a high-fat diet.

To evaluate the effects of melatonin (MEL) on the expression of toll-like receptor-4 (TLR4); myeloid differentiation primary response protein-88 (MyD88); TIR-domain-containing adapter-inducing interferon-ß (TRIF); IFN regulatory-factor-3 (IRF-3); nuclear factor kappa-B (NF-κB); plasma concentrations of interleukin-1ß (IL-1ß) and lipopolysaccharide (LPS); and lipid profile of rats with apical periodontitis (AP) fed on a high-fat diet (HFD). Eighty 60-day-old rats were divided into eight groups: control, AP, HFD, HFDAP, CNMEL, APMEL, HFDMEL and HFDAPMEL. HFD groups were fed on a HFD for 107 days. On day 7, experimental AP was induced in the AP groups, and after 70 days, MEL (5 mg/kg) was administered to the MEL groups for 30 days. Plasma concentrations of LPS and IL-1ß were analyzed using enzyme-linked immunosorbent assay, and the lipid profile was analyzed using biochemical tests. The expression of proteins involved in the TLR4 pathway (TLR4, MyD88, TRIF, IRF-3 and NF-κB) in the gastrocnemius muscle (GM) was evaluated using western blotting and qRT-PCR. Treatment with MEL decreased IRF-3 protein expression in GM and IL-1ß plasma concentration in the APMEL and HFDMEL groups. Reduction in LPS plasma concentration was reported only in the HFDMEL group. Additionally, a decrease in LDL and an increase in HDL were observed in the HFDMEL and HFDAPMEL groups. Treatment with MEL exhibited anti-inflammatory and anti-hyperlipidemic effects attributed to HFD and AP by reducing the plasma concentrations of IL-1ß and LPS in addition to reducing IRF-3 protein expression in the GM, which is associated with the production of inflammatory cytokines.

Effect of maternal true combined endodontic-periodontal lesion on insulin and inflammatory pathway in adult offspring.

BACKGROUND: Maternal periodontal disease (PED) and apical periodontitis (AP) are associated insulin resistance (IR), increased tumor necrosis factor-α (TNF-α) levels, and alterations in insulin signaling (IS) in the gastrocnemius muscle (GM) of adult offspring. TNF-α stimulates I kappa B kinase (IKK) and c-Jun N-terminal protein kinase (JNK), resulting in IS attenuation. However, studies that investigated the maternal true endodontic-periodontal lesion (EPL) in offspring are scarce, and in this case, the impact could be even higher. This study aimed to evaluate the effects of EPL on the IR, IS, and inflammatory pathways on the offspring GM. METHODS: Female Wistar rats were distributed into control, AP, PED, and EPL groups. After 30 days of oral inflammation induction, rats from all groups were allowed to mate with healthy rats. The body weight of the offspring was assessed from birth to 75 days of age. After 75 days, the following measurements were performed: glycemia, insulinemia, IR, TNF-α content, and IKKα/ß, JNK, pp185 (Tyr), and IRS-1 (Ser) phosphorylation status in the GM. RESULTS: Maternal PED and EPL were associated with low birth weights. All maternal oral inflammations promoted IR and IS impairment in the GM and only maternal PED and EPL caused an increase in TNF-α content and IKKα/ß phosphorylation status in the GM of offspring. The offspring of the rats with EPL group showed worsening of metabolic changes when compared with offspring of rats with AP or PED. CONCLUSION: Association of maternal AP and PED promoted a more pronounced worsening in the health of the adult offspring.

Curcumin reduces inflammation in rat apical periodontitis.

AIM: The aim of the study was to evaluate the effect of systemic curcumin administration on the severity of apical periodontitis (AP). METHODOLOGY: Forty male Wistar rats weighing 250-280 g each, age 2.5 months, were distributed into four groups (n = 10): control untreated rats (C), control rats treated with curcumin (CUR), rats with pulp exposure-induced apical periodontitis (AP) and rats with pulp exposure-induced apical periodontitis treated with curcumin (AP-CUR). Curcumin treatment was administered orally once daily for 15 days before pulp exposure and continued for 30 days after pulp exposure. The rats were sacrificed at 30 days, and the jaws were collected and reconstructed in a programme specific for micro-CT. The jaws were processed for analysis of the inflammatory process using haematoxylin and eosin staining and immunohistochemical assays for interleukin tumour necrosis factor alpha (TNF-α), interleukin (Il)-6 and Il-1ß. Tartrate-resistant acid phosphatase (TRAP) and osteocalcin (OCN) staining were used to analyse the resorptive process on the bone surface of periapical area. Kruskal-Wallis with Dunn's test was performed for nonparametric data and anova with Tukey's test for parametric data, p < .05. RESULTS: Micro-CT revealed no statistically significant differences in bone resorption between the AP and AP-CUR groups (p > .05). The levels of inflammatory cell infiltration and immunoreactivity for the proinflammatory cytokines TNF-α, Il-6 and Il-1ß were significantly higher in the periapical lesions of the AP group than in the AP-CUR group (p < .05). The number of TRAP-positive multinucleated cells was higher in the AP group than in the AP-CUR group (p < .05). In OCN-positive cells, no differences were observed between the AP and AP-CUR groups (p > .05). CONCLUSIONS: Oral supplementation with curcumin had a significant effect on the AP severity in rats, suggesting an anti-inflammatory effect of curcumin on AP development.

Method 300: a complementary teaching methodology in Dentistry.

This study evaluated Method 300, a complementary teaching methodology in Dentistry. Thirty participants were divided into 6 groups according to the scores obtained in a placement test ranging from 0 to 10. Students with scores lower than 6 were classified as having poor academic performance; students with scores equal to or greater than 6 were considered as having good academic performance. Each group included at least one student with good performance. Our methodology consisted of two application cycles, each including one different test; however, only students with low performance could undergo the second testing. Students held meetings twice a week for one hour and thirty minutes. Of the 54 students initially enrolled in the subject, 24 dropped out, leaving 30 students who completed all the proposed activities. In cycle 1, 24 (80%) students showed poor academic performance and 6 (20%) good. Students with poor performance in P1 significantly improved after P1 300 test application (P < 0.001). After cycle 1 activities, all 30 participants showed significant improvement. In cycle 2, the number of students with good performance tripled when compared to cycle 1, resulting in a decrease in the number of students with poor performance (P = 0.205). Results show that the Method 300 is an important teaching-learning resource in Dentistry, to be used as a complementary methodology to lectures.

Melatonin as an adjunctive treatment on dental procedures: A systematic review.

The systematic review tried to answer the following question: Does the melatonin administered systemically or topically ameliorate patients involved with oral health conditions or dental procedures? The systematic review has been registered in the PROSPERO (2021CRD42021095959). Eligibility criteria included only randomized controlled clinical trials (RCTs) with at least 10 participants that compared patients that received melatonin as a treatment before and/or after their oral intervention topically or systemically, with control patients. A search was performed in PubMed/MEDLINE, Web of Science, Cochrane Library, and Academic Google databases for articles up to February 2021. The Cochrane risk-of-bias tool for randomized clinical trials was used and revealed that the studies included presented low risk of bias for the majority of criteria assessed. It was selected 25 articles, of which only six did not demonstrate positive effects and three presented null effects with the use of melatonin. Melatonin has improved the inflammatory response in periodontal disease, dental surgeries, and mucositis of head and neck oncologic irradiated patients. In addition, it showed anxiolytic potential in patients that were submitted to dental procedures. In conclusion, melatonin favored the treatment of oral changes when used topically and systemically.