Insulin resistance and periodontitis: Mediation by blood pressure.

AIM: This study investigated the association between the triglyceride-glucose (TyG) index, a surrogate marker of insulin resistance, and moderate/severe periodontitis and the role of blood pressure as a mediator in this association. A second aim was to assess the role of cardiometabolic conditions such as obesity, hypertension, and dyslipidemia as potential effect modifiers. METHODS: Data from 5733 US adults aged 30-64 years and with complete periodontal examination were analyzed (NHANES 2011-2014). Participants were classified as having moderate/severe periodontitis or mild/no periodontitis according to the CDC/AAP criteria as the outcome. The exposure was the TyG index, while both systolic (SBP), and diastolic (DBP) blood pressure were tested as mediators using parametric g-formula. Analyses were adjusted for relevant confounders, namely, age, sex, ethnicity, poverty-income ratio, and smoking, using inverse probability treatment weighting. Obesity status (based on a body mass index ≥30 kg/m2), self-report of hypertension and dyslipidemia (calculated based on the thresholds provided by National Cholesterol Education Program-Adult Treatment Panel-III) were tested as effect modifiers. RESULTS: The findings showed the TyG index to be associated with increased odds of moderate/severe periodontitis [odds ratio (OR), 95% confidence interval (CI) = 1.17 (1.11-1.23)], with 50% of the total effect mediated by SBP. Stratified analysis showed a stronger association in individuals with obesity, hypertension, and dyslipidemia compared to those without these conditions. However, in those taking anti-hypertensive medications, the association was partially mitigated. Sensitivity analysis using imputed data showed consistent results. CONCLUSION: The TyG index was associated with increased odds of moderate/severe periodontitis, especially in individuals with obesity, hypertension, and dyslipidemia. SBP levels partially mediated this association.

Oral conditions are associated with salt taste disability among American adults.

AIM: To explore the association between oral conditions and their interaction with salt taste disability among American adults. METHODS: Data from the 2013-2014 NHANES cycle were used (n = 2373). The exposures were periodontitis, defined by the 2017 EFP-AAP classification, dental caries, missing teeth, and edentulism, as per the DMF-T index, and xerostomia. The outcome was salt taste disability, objectively assessed. Covariates included sex, age, educational level, poverty index, obesity, diabetes, smoking, alcohol consumption, and medications related to mouth dryness. Weighted multivariable logistic regression modeling was used to evaluate the relationship between oral conditions and their interaction and salt taste disability. RESULTS: Participants who reported xerostomia were more likely to have salt taste disability (OR 2.42; 95%CI 1.44-4.07), especially those older than 60 years (OR 3.63; 95%CI 1.72-7.63). Among participants aged 40-59, xerostomia increased the chance of salt taste disability; however, the confidence interval included the null value. The interactions between xerostomia and edentulism increased the chance of salt taste disability. CONCLUSION: Oral conditions seem to influence the ability to taste salt. Dental professionals may help identify individuals with taste alterations and raise their awareness of the risk of systemic diseases that require the reduction of salt intake.

Intake and serum levels of micronutrients and chronic oral diseases burden.

OBJECTIVE: To investigate pathways from micronutrient intake and serum levels to Chronic Oral Diseases Burden. METHODS: We analyzed cross-sectional data from NHANES III (n = 7936) and NHANES 2011-2014 (n = 4929). The exposure was the intake and serum levels of vitamin D, calcium, and phosphorus. Considering the high correlation of those micronutrients in the diet, they were analyzed as a latent variable dubbed Micronutrient intake. The outcome was the Chronic Oral Diseases Burden, a latent variable formed by probing pocket depth, clinical attachment loss, furcation involvement, caries, and missing teeth. Pathways triggered by gender, age, socioeconomic status, obesity, smoking, and alcohol were also estimated using structural equation modeling. RESULTS: In both NHANES cycles, micronutrient intake (p-value < 0.05) and vitamin D serum (p-value < 0.05) were associated with a lower Chronic Oral Diseases Burden. Micronutrient intake reduced the Chronic Oral Diseases Burden via vitamin D serum (p-value < 0.05). Obesity increased the Chronic Oral Diseases Burden by reducing vitamin D serum (p-value < 0.05). CONCLUSION: Higher micronutrient intake and higher vitamin D serum levels seem to reduce Chronic Oral Diseases Burden. Healthy diet policies may jointly tackle caries, periodontitis, obesity, and other non-communicable diseases.

Precursors of insulin resistance underlying periodontitis in adolescents aged 17-18 years.

OBJECTIVE: To investigate the association between insulin resistance markers and periodontitis in adolescents, analyzing confounder variables and the adiposity as a mediator. METHODS: This is population-based study is representative of adolescents aged 17-18 years from public schools in São Luís, Brazil (n = 405). Insulin resistance was assessed using the Model of Assessment of the Homeostasis of the Insulin Resistance Index (HOMA-IR) and its percussor triglycerides/HDL-cholesterol ratio (TG/HDL-c). The outcome was Initial Periodontitis, a latent variable estimated by the common variance shared among bleeding on probing, probing depth ≥ 4 mm, and clinical attachment loss ≥ 4 mm. The association between insulin resistance and Initial Periodontitis was modeled via pathways triggered by socioeconomic status, smoking, alcohol, and Adiposity, using structural equation modeling. RESULTS: Higher TG/HDL-c was directly associated with higher Initial Periodontitis (standardized coefficient [SC] = 0.130, p < 0.001). HOMA-IR was not associated with periodontal outcome (SC = 0.023, p = 0.075), but it was with Adiposity (SC = 0.495, p < 0.001). Higher TG/HDL-c was associated with Adiposity (SC = 0.202, p < 0.001). CONCLUSION: The insulin resistance markers were associated with early signs of periodontal breakdown among adolescents, suggesting a possible relationship between diabetes and periodontitis commences early in life.

JAK/STAT as a Potential Therapeutic Target for Osteolytic Diseases.

Several cytokines with major biological functions in inflammatory diseases exert their functions through the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signal transduction pathway. JAKs phosphorylate the cytoplasmic domain of the receptor, inducing the activation of its substrates, mainly the proteins known as STATs. STATs bind to these phosphorylated tyrosine residues and translocate from the cytoplasm to the nucleus, further regulating the transcription of several genes that regulate the inflammatory response. The JAK/STAT signaling pathway plays a critical role in the pathogenesis of inflammatory diseases. There is also increasing evidence indicating that the persistent activation of the JAK/STAT signaling pathway is related to several inflammatory bone (osteolytic) diseases. However, the specific mechanism remains to be clarified. JAK/STAT signaling pathway inhibitors have gained major scientific interest to explore their potential in the prevention of the destruction of mineralized tissues in osteolytic diseases. Here, our review highlights the importance of the JAK/STAT signaling pathway in inflammation-induced bone resorption and presents the results of clinical studies and experimental models of JAK inhibitors in osteolytic diseases.

Cytokine profiles and the dynamic of gingivitis development in humans.

AIM: To investigate the relationship between cytokine profiles and "fast" and "slow" patterns of gingival inflammation development. MATERIALS AND METHODS: Forty-two adults participated in an experimental gingivitis study, comprising a 2-week hygiene phase (clinical examination and professional cleaning); a 3-week induction phase (absence of oral hygiene); and a 2-week resolution phase (re-establishment of oral hygiene). Plaque and gingival inflammation scores were assessed. Interferon-gamma (IFN-γ), interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, and tumour necrosis factor-alpha (TNF-α) from gingival crevicular fluid were collected and measured by multiplex ELISA. Group-based-trajectory-modelling (GBTM) was used to model cytokine profiles over the induction phase. The effect of gingival inflammation on cytokine levels over time was estimated with mixed-effects modelling. RESULTS: GBTM analysis revealed two cytokine profiles, "non-organized response" (IL-4, IL-6, IL-8, IL-12, and IL-13) and "organized response" (IL-2, IL-10, and TNF-α). Among the "slow" responders, neither cytokine profile was associated with gingivitis. In contrast, a "fast" response was associated with a higher "non-organized response" factor (coef. 0.14) and a lower "organized response" factor (coef. -0.03). CONCLUSION: A "fast" gingivitis development was associated with a higher "non-organized response" and a lower "organized response", which may elucidate the role of individual variability in gingivitis susceptibility.

The association between halitosis and oral-health-related quality of life: A systematic review and meta-analysis.

AIM: To investigate whether halitosis is associated with impaired oral-health-related quality of life (OHRQoL). MATERIALS AND METHODS: This is a systematic review of the literature. Electronic searches were performed in PubMed via Medline, Web of Science, Scopus, and EMBASE up to and including June 2021. Observational studies that assessed halitosis in association with OHRQoL were included. The pooled standardized mean difference (SMD) was estimated by meta-analysis. RESULTS: Thirteen studies were included in the review; however, the meta-analysis included only 10 studies, all cross-sectional, comprising 2692 individuals. The overall meta-analysis showed an association between halitosis and impaired OHRQoL (SMD 0.51; 95% confidence interval 0.27-0.75). Subgroup analyses, however, indicated that this association remained only among adults. Neither the OHRQoL instrument nor the halitosis assessment method, or the cultural background, influenced the pooled estimates. Meta-regression analyses revealed that the OHRQoL instrument, the halitosis assessment method, and the sample composition did not explain the between-study heterogeneity. Methodological quality appeared to explain 20% of the overall heterogeneity, as studies with high risk of bias overestimated the magnitude of the association. CONCLUSION: Our findings suggest that halitosis is associated with impaired OHRQoL.

Use of air polishing for supra- and subgingival biofilm removal for treatment of residual periodontal pockets and supportive periodontal care: a systematic review.

AIM: To systematically review the literature to compare the efficacy of air polishing to hand or ultrasonic instrumentation to reduce periodontal inflammation during treatment of residual pockets or supportive periodontal care. METHODS: Electronic searches were performed in five different databases, and two databases were used to capture the "grey literature partially." Clinical trials that compared the use of an air-polishing device to either conventional scaling and root planing (hand and/or ultrasonic instrumentation) or no treatment during periodontal therapy were included without restriction of year and publication status. The Joanna Briggs Institute instrument for clinical trials was used to appraise the studies critically. The results were submitted to qualitative descriptive analysis. The systematic review protocol was registered in PROSPERO (CRD420220156176). RESULTS: Electronic searches found 1100 hits published between 2008 and 2019. Thirteen studies were included in the review, out of which four had a follow-up longer than 180 days. Results indicated no differences between the efficacy of air polishing and hand or ultrasonic instruments to reduce periodontal inflammation. CONCLUSIONS: Our findings suggest that there is no difference in the efficacy of air polishing and hand or ultrasonic instrumentation to control biofilm and reduce periodontal inflammation. However, these findings must be carefully interpreted owing to methodological issues, including a short follow-up, and a potential conflict of interest related to industry funding. CLINICAL RELEVANCE: Air polishing for biofilm control may be used as an alternative to hand and ultrasonic instrumentation to reduce periodontal inflammation during treatment of residual pockets or supportive periodontal care.

Early-predictors of marginal bone loss around morse taper connection implants loaded with single crowns: A prospective longitudinal study.

BACKGROUND AND OBJECTIVE: Few studies estimated the joint effect of implant design (length and diameter), peri-implant, and occlusal variables on early marginal bone loss. The monitoring of these factors during the first year after implant loading may be effective in preventing early implant failure. This prospective longitudinal study aimed to identify early-predictors of marginal bone loss around morse-tapered connection implants 12 months after implant loading. METHODS: Participants (n = 33) received 109 morse taper implants inserted subcrestally (diameter: 3.5 to 5 mm, length: 6 to 15 mm) loaded with single crowns. Implants were radiographically examined at the implant placement (baseline) and 12 months after prosthetic loading. Implant, peri-implant, and occlusal-related independent variables were analyzed by decision tree analysis. Mixed-effects multilevel analysis was used to estimate adjusted predictive values of marginal bone loss based on the early-predictors identified in decision tree analysis. RESULTS: Higher marginal bone loss was observed at mesial (mean of 0.87 mm; ranged from 0.5 to 1.19) than at distal sites (mean of 0.73 mm; ranged from 0.4 to 1.12 mm). The predictive model revealed of the largest marginal bone loss in association with cement-retained prostheses, a platform diameter of 3.5 mm, papilla sizes up to 2 mm, keratinized mucosa width inferior to 3 mm, implant lengths above 8.5 mm, inadequate occlusal relations, presence of bleeding on probing and deep peri-implant pocket. CONCLUSION: As implant dimensions, peri-implant and occlusal-related factors were associated with early marginal bone loss around morse taper implant, intervention in these factors might prevent early marginal bone loss.

Periodontitis and self-reported halitosis among young adults from the 1982 Pelotas Birth Cohort.

OBJECTIVE: To investigate the association between periodontitis and self-reported halitosis among young adults, and whether there is an interaction between the effects of smoking and periodontitis on halitosis. METHODS: Data from the 1982 Pelotas birth cohort, Brazil, were used. The controlled direct effect of periodontitis on self-reported halitosis, not mediated by tongue coating, was estimated using marginal structural modeling. In addition, an interaction between the effects of smoking and periodontitis on halitosis was also tested. Confounders comprised sociodemographic information, obesity, diabetes, and oral hygiene habits. RESULTS: The controlled direct effect of periodontitis on halitosis not mediated by tongue coating showed that individuals with periodontitis had 90% higher risk of self-reporting halitosis (RR 1.90) compared to healthy individuals. Individuals with mild periodontitis had twice the risk of reporting halitosis than periodontally healthy individuals (RR 2.31). We also found an interaction between the effects of smoking and periodontitis on halitosis, as noted among smokers with mild (RR 2.91) and moderate-to-severe periodontitis (RR 5.84). CONCLUSION: There is a controlled direct effect of periodontitis on halitosis not mediated by tongue coating. Additionally, an interaction between the effects of smoking and periodontitis on halitosis was also detected.

Impact of Smoking Cessation on Periodontitis: A Systematic Review and Meta-analysis of Prospective Longitudinal Observational and Interventional Studies.

AIMS: This systematic review aimed to estimate the effect of tobacco smoking cessation on the risk for periodontitis compared to the risk among never-smokers and to evaluate the effect of tobacco smoking cessation on the clinical outcomes of nonsurgical periodontal treatment. METHODS: Electronic searches were performed in PubMed, Scopus, and Embase. Search strategy included MeSH and free terms: periodontitis, periodontal diseases, smoking, tobacco use, tobacco, tobacco products, cigarette, pipe, and cigar. Only original prospective longitudinal observational and interventional studies that investigated the association between smoking cessation and periodontitis onset or progression were included. Meta-analyses were conducted to summarize the evidence. RESULTS: A total of 2743 articles were identified in electronic searches; out of which only six were included in the meta-analysis. Pooled estimates showed that the risk of periodontitis incidence or progression among those who quit smoking was not significantly different from the risk for never-smokers (risk ratio [RR] = 0.97; 95% confidence interval [CI] = 0.87% to 1.08%). Smokers had approximately 80% higher risk of periodontitis than quitters (RR = 1.79; 95% CI = 1.36% to 2.35%) and never-smokers (RR = 1.82; 95% CI = 1.43% to 2.31%). Periodontal therapy resulted in up to 0.2 mm (95% CI = -0.32% to -0.08%) higher gain in attachment level and extra 0.32 mm (95% CI = 0.07% to 0.52%) reduction in pocket depth among quitters over nonquitters after short follow-up (12-24 months). CONCLUSIONS: Few studies on the topic were identified. Smoking cessation reduced the risk for periodontitis onset and progression, and improved the outcomes of nonsurgical periodontal therapy. IMPLICATIONS: This review provides the first quantitative evidence of the impact of smoking cessation on the risk for periodontitis onset and progression. The findings have demonstrated that the risk for periodontitis becomes comparable to that of never-smokers and that nonsurgical periodontal treatment outcomes improve after smoking cessation. Dental professionals ought to consider smoking cessation interventions as a relevant component of the periodontal therapy.

Is there an association between depression and periodontitis? A birth cohort study.

AIM: To investigate the association between depression and periodontitis among adults enrolled in the 1982 Pelotas Birth Cohort, Brazil. MATERIALS AND METHODS: Major depressive episode (MDE) and severity of depressive symptoms obtained in 2012 were considered the exposure of this study. In 2013, periodontitis, the outcome of interest, was clinically assessed and two different case definitions were used: the CDC/AAP and a combination of clinical attachment loss (CAL) and bleeding on probing (BOP) simultaneously. Serum levels of C-reactive protein and frequency of dental flossing were defined as mediators while confounders comprised a set of variables collected throughout the life-course of the participants. The parametric g-formula was used to test the direct, indirect and total effects of depression on periodontitis. RESULTS: 539 participants were clinically examined. Individuals with depressive symptoms presented higher risk of periodontitis (risk ratio [RR] 1.19). The presence of depressive symptoms was also associated with moderate/severe periodontitis (total effect RR 1.18). None of the associations was mediated by flossing or C-reactive protein levels. Finally, neither the presence of depressive symptoms nor the presence of major depression was associated with the combination of CAL+BOP. CONCLUSIONS: A positive association between depressive symptoms and periodontitis and moderate/severe periodontitis was found. MDE was not associated with periodontitis.

Clinical comparison of the effectiveness of 7- and 14-day intracanal medications in root canal disinfection and inflammatory cytokines.

OBJECTIVE: This clinical study compared the effectiveness of 7- and 14-day intracanal medications in the reduction of bacteria/endotoxins from primarily infected root canals and determined their antigenicity against macrophages through the levels of cytokines. METHODS: Seventy-two primarily infected teeth were randomly divided into six groups according to medication and time of application: 7-day groups = G1, Ca(OH)2 + saline solution (SSL); G2, Ca(OH)2 + 2% chlorhexidine (CHX) gel; and G3, 2% CHX gel and 14-day groups = G4, Ca(OH)2 + SSL; G5, Ca(OH)2 + 2% CHX gel; and G6, 2% CHX gel (all groups, n = 12). Bacterial and endotoxin samples were collected from root canals and inflammatory cytokines of macrophages supernatants. Culture techniques were used to determine bacterial counts and limulus amebocyte lysate (LAL) assay to quantify endotoxins. IL-1ß, TNF-α, and PGE2 were measured by ELISA-assay. RESULTS: With regard to the bacterial reduction, no differences were found between all protocols tested (p > 0.05). The CHX protocols (G3 and G6) exhibited the lowest effectiveness against endotoxins (p < 0.05). All protocols were effective in lowering the levels of IL-1ß, TNF-α, and PGE2 (p < 0.05), with no difference between the medications tested on days 7 or 14 (p > 0.05). Particularly, the 7-day CHX-protocol (G3) exhibited the lowest effectiveness in lowering the levels of most cytokines compared to the 14-day protocols (G6) (p < 0.05). CONCLUSIONS: All the 7- and 14-day intracanal medications were effective in reducing bacteria and endotoxins as well as in lowering the levels of inflammatory cytokines, with CHX showing limited effectiveness against endotoxins. Moreover, 7-day CHX-protocol exhibited the lowest effectiveness in lowering the levels of most cytokines compared to the 14-day protocols. CLINICAL SIGNIFICANCE: Seven-day CHX protocol is the less effective protocol and should be carefully applied by the clinician.

Estimated prevalence of halitosis: a systematic review and meta-regression analysis.

OBJECTIVE: This study aims to conduct a systematic review to determine the prevalence of halitosis in adolescents and adults. METHODS: Electronic searches were performed using four different databases without restrictions: PubMed, Scopus, Web of Science, and SciELO. Population-based observational studies that provided data about the prevalence of halitosis in adolescents and adults were included. Additionally, meta-analyses, meta-regression, and sensitivity analyses were conducted to synthesize the evidence. RESULTS: A total of 584 articles were initially found and considered for title and abstract evaluation. Thirteen articles met inclusion criteria. The combined prevalence of halitosis was found to be 31.8% (95% CI 24.6-39.0%). Methodological aspects such as the year of publication and the socioeconomic status of the country where the study was conducted seemed to influence the prevalence of halitosis. CONCLUSIONS: Our results demonstrated that the estimated prevalence of halitosis was 31.8%, with high heterogeneity between studies. The results suggest a worldwide trend towards a rise in halitosis prevalence. CLINICAL RELEVANCE: Given the high prevalence of halitosis and its complex etiology, dental professionals should be aware of their roles in halitosis prevention and treatment.

Is periodontitis associated with halitosis? A systematic review and meta-regression analysis.

AIM: To systematically review the literature in order to investigate a potential association between periodontitis and halitosis. METHODS: Electronic searches were performed in four different databases: PubMed, Scopus, Web of Science and Scielo. Population-based observational studies that tested the association between periodontitis and halitosis were included. Additionally, meta-analysis, meta-regression and subgroup analyses were performed to synthesize the evidence. RESULTS: A total of 1,107 articles were identified in electronic searches; out of which, five were included within the meta-analysis. Pooled estimates revealed that individuals with periodontitis presented 3.16 times higher odds (OR 3.16; 95% CI: 1.12-8.95) of having halitosis. Meta-regression and subgroups analyses showed that criteria used for halitosis and periodontitis assessment explained nearly 45% and 24% of heterogeneity between studies, respectively. CONCLUSIONS: Positive association between periodontitis and halitosis was found in pooled results of population-based observational studies. However, this evidence is derived from cross-sectional studies.

Does periodontal treatment have an effect on clinical and immunological parameters of periodontal disease in obese subjects? A systematic review and meta-analysis.

AIM: The aim of this study was to systematically review the literature to answer the questions: (i) "Is periodontal treatment effective to improve clinical and immunological conditions in obese subjects?"; (ii) "Do obese subjects present different clinical and immunological response after periodontal therapy when compared to non-obese subjects?" METHODS: Searches were performed in six databases up to August 2014. Interventional studies were included if the following data were described: (1) Obesity/overweight assessment; (2) definition of periodontal disease; (3) periodontal therapy; (4) inflammatory marker in serum/plasma, and/or clinical parameters of periodontal disease. Assessment of quality was performed with the Downs and Black scale. Meta-analyses were conducted with the available data. RESULTS: Of 489 articles, 5 were included, and only 3 proceeded to meta-analysis of clinical outcomes. Included studies presented fair methodological quality. Statistical analysis demonstrated that periodontal therapy in obese subjects was effective to improve clinical outcomes. No clinical differences between post-therapy results of obese and non-obese were observed. Effects of periodontal therapy on inflammatory markers remain unclear. CONCLUSIONS: Periodontal treatment seems to be effective to improve healing in obese individuals. No differences on periodontal healing between obese and non-obese subjects were observed; however, only limited and fragile base of evidence was available for analysis. CLINICAL RELEVANCE: Periodontal treatment is effective to improve clinical and immunological periodontal parameters in adults. Also, obesity seems to not modify the periodontal healing after treatment.

Is weight gain associated with the incidence of periodontitis? A systematic review and meta-analysis.

AIM: This study aimed to conduct a systematic review assessing the effects of weight gain on the incidence of periodontitis in adults. METHODS: Electronic searches in four databases were performed up to and including February 2015. Only prospective longitudinal studies assessing the association between weight gain and the incidence of periodontitis in adults were eligible to be included in this study. All studies should state a clear description of nutritional status (Body Mass Index; Waist Circumference) as well as the case definition of periodontitis. Pooled relative risks (RR) for becoming overweight and obese on the incidence of periodontitis were estimated by meta-analysis. Quality was assessed with the Newcastle-Ottawa scale for cohort studies. RESULTS: Five articles were included in this review and meta-analysis with 42,198 subjects enrolled. Subjects who became overweight and obese presented higher risk to develop new cases of periodontitis (RR 1.13; 95%CI 1.06-1.20 and RR 1.33 95%CI 1.21-1.47 respectively) compared with counterparts who stayed in normal weight. CONCLUSIONS: A clear positive association between weight gain and new cases of periodontitis was found. However, these results are originated from limited evidence. Thus, more studies with longitudinal prospective design are needed.

Endodontic retreatment: clinical comparison of reciprocating systems versus rotary system in disinfecting root canals.

INTRODUCTION: This clinical study was conducted to compare the effectiveness of single-file reciprocating systems and rotary systems in removing endotoxins and cultivable bacteria in endodontic retreatment. METHODS: Thirty endodontically treated teeth with post-treatment apical periodontitis were selected. The specimens were divided into three groups according to the system used: WaveOne (n = 10), Reciproc instrument (n = 10), and ProTaper Universal Retreatment system (n = 10). Samples were collected before and after chemomechanical preparation. The irrigation was performed by using 2.5% sodium hypochlorite. A chromogenic limulus amebocyte lysate assay test was used to quantify endotoxins. Culture techniques were used to determine bacterial colony-forming unit counts. RESULTS: At baseline, endotoxins and cultivable bacteria were recovered from 100% of the root canal samples in a median value of 5.84 EU/mL and 4.98 × 10(3) CFU/mL, respectively. After CMP, no differences were found in the median percentage values of endotoxin reduction achieved with reciprocating systems-WaveOne [94.11%] and Reciproc [93.29%] and with rotary systems-ProTaper [94.98%] (P > 0.05). Both single-file reciprocating systems [WaveOne (98.27%) and Reciproc (99.54%)] and rotary system [ProTaper (98.73%)] were effective in reducing bacterial load (P > 0.05). Moreover, no differences were found among the systems tested. CONCLUSIONS: The Reciproc and WaveOne reciprocating systems were as effective as the ProTaper system for removal of endotoxins and bacteria in endodontic retreatment. CLINICAL RELEVANCE: All systems tested were effective to remove cultivable bacteria and endotoxin in endodontic retreatment. As no differences among systems were observed, it is possible to suggest that clinicians should choose the preferred technique to perform endodontic.