Comparison of conventional and contemporary root canal disinfection protocols against bacteria, lipoteichoic acid (LTA), and lipopolysaccharide (LPS).

This study devised a dual-species biofilm model to investigate bacteria, lipoteichoic acid (LTA), and lipopolysaccharide (LPS) simultaneously, and compared the efficacy of conventional and contemporary disinfection protocols. Seventy single-rooted mandibular premolars were included. Fourteen teeth were negative control, and 56 teeth were infected with 3-week-old E. faecalis and E. coli GFP biofilm. Fourteen/56 teeth were positive control, with seven teeth processed for CLSM analysis and seven teeth sampled with paper points (PPs) and cryogenically ground for bacterial, LTA, and LPS analyses. Forty-two teeth were randomly divided into three groups: GWS (GentleWave system) + MIT (minimally invasive technique), PUI (passive ultrasonic irrigation) + CIT (conventional instrumentation technique), and XP-EF (XP-endo Finisher) + CIT (All, n = 14). Samples were collected before (s1) and after disinfection (s2) with PPs and after cryogenically ground (s3). CFUs were counted, and LTA and LPS were quantified with LTA-ELISA and LAL assay, respectively. XP-EF was as effective as PUI (p > 0.05). GWS + MIT was the most effective disinfection protocol against bacteria, LTA, and LPS (p < 0.05). In conclusion, PUI, XP-EF, and GWS were highly effective against bacteria, LTA, and LPS, with GWS being the most effective.

Comparison of GentleWave system and passive ultrasonic irrigation with minimally invasive and conventional instrumentation against LPS in infected root canals.

This study compared the effectiveness of GentleWave system (GWS) and passive ultrasonic irrigation (PUI) in removing lipopolysaccharides (LPS) from infected root canals after minimally invasive (MIT) and conventional instrumentation (CIT) techniques. Sixty first premolars with two roots were inoculated with fluorescent LPS conjugate (Alexa Fluor 594). Of those, twelve were dentin pretreated, inoculated with fluorescent LPS conjugate, and submitted to confocal laser scanning microscopy (CLSM) to validate the LPS-infection model. Forty-eight teeth were randomly divided into treatment groups: GWS + MIT, GWS + CIT, PUI + MIT, and PUI + CIT (all, n = 12). Teeth were instrumented with Vortex Blue rotary file size 15/0.04 for MIT and 35/0.04 for CIT. Samples were collected before (s1) and after a root canal procedure (s2) and after cryogenically ground the teeth (s3) for intraradicular LPS analysis. LPS were quantified with LAL assay (KQCL test). GWS + MIT and GWS + CIT were the most effective protocols against LPS, with no difference between them (p > 0.05). PUI + CIT was more effective than PUI + MIT (p < 0.05) but less effective than GWS + MIT and GWS + CIT. GWS was the most effective protocol against LPS in infected root canals using MIT and CIT techniques.

Clinical influence of calcium hydroxide intracanal medications on matrix metalloproteinases and tissue inhibitors of metalloproteinases in apical periodontitis.

OBJECTIVES: This study investigated the influence of calcium hydroxide intracanal medications on the levels of metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in apical periodontitis (AP). MATERIALS AND METHODS: Twenty primarily infected root canals with AP were randomly divided into two groups: Ca(OH)2 + sterile saline solution (SSL) group and Ca(OH)2 + 2% chlorhexidine gel (CHX gel) group. We collected samples from the periradicular tissue fluid (PTF) before (s1) and after 14 days of intracanal medication (s2). MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 were measured by ELISA assay. RESULTS: MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 were detected in all PTF samples at s1 and s2 (20/20). At s1, MMP-2 and MMP-9 were detected at higher levels than MMP-1 (p < .05). Higher levels of TIMP-1 than TIMP-2 were found in AP (p < .05). Additionally, we detected higher MMP-1, MMP-2, and MMP-9 over TIMP-1 and TIMP-2 levels in AP (p < .05). At s2, Ca(OH)2 + SSL was as effective as Ca(OH)2 + 2% CHX gel in lowering the levels of MMP-1, MMP-2, and MMP-9 after 14 days of intracanal medication, with no significant difference between them (p > .05). Both Ca(OH) 2 intracanal medications had no significant impact on the levels of TIMP-1 and TIMP-2 (both p > .05). At s2, TIMP-1 levels were higher than TIMP-2 (p < .05). Moreover, there were positive correlations between the levels of MMP-1 and TIMP-1 and MMP-1 and TIMP-2 (p < .05). CONCLUSIONS: Calcium hydroxide medications effectively lowered the levels of MMP-1, MMP-2, and MMP-9 in periapical tissues after 14 days of treatment, with no difference between them. Moreover, the calcium hydroxide intracanal medications tested here had no impact in TIMP-1 and TIMP-2 in periapical tissues. CLINICAL RELEVANCE: MMPs and TIMPs play an essential role in the degradation of the extracellular matrix. The imbalance MMPs and TIMPs can cause periapical tissue destruction. Therefore, the reestablishment of the balance between activated MMPs and TIMPs with root canal therapy is essential to restore tissue homeostasis.

Comparison of the effectiveness of single- and multiple-sessions disinfection protocols against endotoxins in root canal infections: systematic review and meta-analysis.

This systematic review (SR) addressed the following common clinical question: What is more effective in reducing or eliminating endotoxin in endodontic infections-single or multiple-session treatments using calcium hydroxide medications? Literature searches of Medline/PubMed, Embase, Cochrane Library, Scielo, Science Direct, Web of Knowledge, Scopus, and Google Scholar databases. Two reviewers independently assessed the eligibility for inclusion, extracted data, and evaluated the quality of the studies using the risk of bias tools. Electronic searches resulted in 358 articles, of which 32 studies were included for full-text assessment, and nine were included in this review. Meta-analysis pooling all the nine studies revealed lower levels of endotoxin for multiple-session treatment (P < 0.001). The sub-group analysis indicated no difference between single-session and 7 days of Ca(OH)2 medication (SMD - 0.32; P = 0.22). However, 14-days (I2 = 80.5%, P < 0.001) and 30-days (I2 = 78.9%, P < 0.01) of Ca(OH)2 medication was more effective than single-session treatment (both, p < 0.001). Overall, Overall, this SR provides evidence to support that multiple-session disinfection protocols with the placement of Ca(OH)2 medications are more effective in reducing the levels of endotoxin from root canal infections compared to single-session when applied for 14 and 30 days.

Assessment of the efficacy of the utilisation of conventional and electric toothbrushes by the older adults.

OBJECTIVE: To evaluate the efficacy of electric and conventional toothbrushes for a group of elderly individuals. BACKGROUND: Although the electric toothbrush has been recommended for elderly individuals, there had previously never been a study regarding its efficacy. MATERIAL AND METHODS: Sixty independent elders of both genders with different oral conditions from the Center Adult Day Vitória, Espírito Santo, Brazil, were randomly divided into two groups of 30 individuals. One group received the Oral B CrossAction Power electric toothbrush, whereas the other received a conventional Bitufo Class 32 soft toothbrush to perform oral hygiene. The bacterial plaque index (O'Leary Plaque Index) and DMFT index were assessed as a measure of oral hygiene and oral health. The data were analysed using the Shapiro-Wilk, Mann-Whitney and Wilcoxon tests. RESULTS: The results of the efficacy of the Oral B Cross Action Power electric toothbrush demonstrated that on the 7th and 15th days, the bacterial plaque indexes were 24.91 ± 12.81 and 22.11 ± 14.46, respectively, which corresponds to a 50.24% removal of bacterial plaque on the 7th and 55.83% on the 15th days. Although the electric toothbrush removed more bacterial plaque than the conventional toothbrush, the difference was not statistically significant. CONCLUSION: Both the conventional and the electric toothbrushes were effective in removing bacterial plaque within the elderly group. More studies are necessary to test the efficacy of electric toothbrushes in relation to conventional toothbrushes for elderly patients.

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.

Does supplemental photodynamic therapy optimize the disinfection of bacteria and endotoxins in one-visit and two-visit root canal therapy? A randomized clinical trial.

AIM: To evaluate the effectiveness of supplemental photodynamic therapy (PDT) in optimizing the removal of bacteria and endotoxins from primarily infected root canals after one-visit and two-visit treatments. METHODOLOGY: Twenty-four primarily infected root canals with apical periodontitis were selected and randomly divided into one-visit (n=12) and two-visit treatment groups (n=12). Chemo-mechanical preparation (CMP) was performed by using the single-file reciprocating technique+2.5% NaOCL and a final rinse with 17% EDTA. The photosensitizer agent (methylene blue 0.1mg/mL) was applied to root canals for 60s before application of laser with a potency of 60mW and energy density of 129J/cm2 for 120s after CMP in the one-visit treatment and after 14-day inter-appointment medication with Ca(OH)2+Saline solution (SSL) in the two-visit treatment. Samples were collected before and after root canal procedures. Endotoxins were quantified by chromogenic limulus amebocyte lysate assay. Culture techniques were used to determine bacterial colony-forming unit counts. RESULTS: Bacteria and endotoxins were detected in 100% of the initial samples, with median values of 1.97×105 CFU/mL and 24.983EU/mL, respectively. The CMP using single-file reciprocating technique was effective in the reduction of bacteria and endotoxins (All, p<0.05). The supplemental PDT was effective in reducing bacterial load in the one-visit (p<0.05) but not in the two-visit treatment after use of Ca(OH)2 medication for 14days (p>0.05). In the two-visit group, after 14days of inter-appointment medication with Ca(OH)2, a significant reduction in the median levels of endotoxins was found in comparison to CMP alone (from 1.041 to 0.094EU/mL) (p<0.05). Despite the type of treatment, the supplemental PDT was not effective against endotoxins (p>0.05). CONCLUSIONS: The photodynamic therapy optimized the disinfection of bacteria from root canals in one-visit but not for two visit treatment modality with the accomplishment of calcium hydroxide medication. Despite the type of treatment, the supplemental PDT was not effective against endotoxins.

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.

Clinical influence of different intracanal medications on Th1-type and Th2-type cytokine responses in apical periodontitis.

INTRODUCTION: This clinical study assessed the influence of different intracanal medications on Th1-type and Th2-type cytokine responses in apical periodontitis and monitored the levels of bacteria from primarily infection during endodontic procedures. METHODS: Thirty primarily infected teeth were randomly divided into 3 groups according to the medication selected: chlorhexidine (CHX), 2% CHX gel; Ca(OH)2/SSL, Ca(OH)2 + SSL; and Ca(OH)2/CHX, Ca(OH)2 + 2% CHX gel (all, n = 10). Bacterial sample was collected from root canals, and the interstitial fluid was sampled from lesions. Culture techniques were used to determine bacterial counts (colony-forming units/mL). Th1 (tumor necrosis factor-α, interferon-γ, and interleukin [IL]-2) and Th2 cytokines (IL-4, IL-5, and IL-13) were measured by enzyme-linked immunosorbent assay. RESULTS: All intracanal medication protocols were effective in reducing the bacterial load from root canals (all P < .05) and lowering the levels of Th1-type cytokines in apical lesions (all P < .05), with no differences between them (P > .05). Both Ca(OH)2 treatment protocols significantly increased the levels of Th2-type cytokines (P < .05), with no differences between them (P > .05). Thus, chlorhexidine medication showed the lowest effectiveness in increasing the levels of Th2-type cytokine. After treatment, regardless of the type of medication, the linear regression analysis indicated the down-regulation of Th2-type cytokines by Th1-type cytokines. CONCLUSIONS: All intracanal medication protocols were effective in reducing bacterial load and lowering the levels of Th1-type cytokines. Thus, the use of Ca(OH)2 medications contributed to the increase in the Th2-type cytokine response in apical periodontitis.

Clinical comparison of the effectiveness of single-file reciprocating systems and rotary systems for removal of endotoxins and cultivable bacteria from primarily infected 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 from primarily infected root canals. METHODS: Forty-eight primarily infected root canals were selected and randomly divided into 4 groups: WaveOne (Dentsply Maillefer, Ballaigues, Switzerland) (n = 12); Reciproc (VDW, Munich, Germany) (n = 12), ProTaper (Dentsply Maillefer) (n = 12), and Mtwo (VDW) (n = 12). 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: In the baseline samples (ie, samples collected before chemomechanical preparation), endotoxins and cultivable bacteria were recovered from 100% of the root canal samples. No differences were found in the median percentage values of endotoxin reduction achieved with reciprocating systems (ie, WaveOne [95.15%] and Reciproc [96.21%]) and with rotary systems (ie, ProTaper [97.98%] and Mtwo [96.34%]) (P < .05). Both single-file reciprocating systems (ie, WaveOne [99.45%] and Reciproc [99.93%]) and rotary systems (ProTaper [99.85%] and Mtwo [99.41%]) were effective in reducing the cultivable bacteria (all P < .05). Moreover, the culture analysis revealed no differences in bacterial load reduction (P > .05). CONCLUSIONS: Both single-file reciprocating systems (ie, WaveOne and Reciproc instruments) and rotary systems (ie, ProTaper and Mtwo instruments) showed similar effectiveness in reducing endotoxins and cultivable bacteria from primarily infected root canals, but they were not able to eliminate them from all root canals analyzed.