Long-term tissue response to bacteria enclosed in a subcutaneous implant that simulates the infected dental root canal

Abstract BACKGROUND: Watertight repair of the dura is imperative after neurosurgical procedures involving the brain or spinal cord because inadequately treated leakage of cerebrospinal fluid (CSF) from punctured dura can have serious consequences such as meningitis, arachnoiditis, or epidural abscess. OBJECTIVE: To assess the efficacy of Evicel Fibrin Sealant (Human) to prevent CSF leakage using a 2.0-cm durotomy mongrel dog repair model and to compare the tissue response with Tisseel (a fibrin sealant) and Duraseal (a synthetic polyethylene glycol [PEG] hydrogel sealant). METHODS: The canine durotomy repair model was used. This well-characterized model assesses the ability of sealants to achieve intraoperative watertight seals of the dura mater, as well as long-term safety and efficacy. This study included 27 mongrel dogs and had a 28-day duration. RESULTS: The 3 sealants were 100% effective in preventing CSF leakage intraoperatively at 15 mm Hg. The 2 fibrin sealants were 100% effective in postoperative sealing; the PEG hydrogel was not. Microscopically, the tissue changes induced by Evicel at the durotomy site were similar in nature except for foamy macrophages seen only with the PEG hydrogel. The extent and severity of adhesions at 28 days were less with the fibrin sealants than with the PEG hydrogel. CONCLUSION: Evicel, a fibrin sealant, was safe and effective in achieving and maintaining a watertight seal of the dura. The performance of the fibrin sealants was similar to that of the synthetic PEG hydrogel sealant with the exception of a Duraseal seal, which leaked.

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Long-term evaluation of crown and root discoloration induced by different endodontic sealers

Brazilian Journal of Oral Sciences ◽

10.20396/bjos.v17i0.8654157 ◽

2018 ◽

Vol 17 ◽

pp. e18483

Author(s):

Beatriz Serrato Coelho ◽

Paula Pontes Garcia ◽

Flávia Sens Fagundes Tomazinho ◽

Leonardo Fernandes Cunha ◽

Denise Piotto Leonardi ◽

...

Keyword(s):

Analysis Of Variance ◽

Root Canal ◽

The Other ◽

Tooth Crown ◽

Root Canal Filling ◽

Color Changes ◽

Term Evaluation ◽

Ah Plus ◽

Endodontic Sealers

Aim: To evaluate crown and root discoloration promoted by different endodontic sealers after root canal filling. Methods: Eighty bovine incisors were prepared and filled with: Endofill, Sealer 26, AH Plus, and MTA Fillapex. Color was recorded using a spectrophotometer before endodontic treatment (T0) and at 24 hours (T1), seven days (T2), 30 days (T3), and 90 days (T4) after treatment. Analyses were performed on the middle and cervical regions of the crown, and on the cervical third of the root, immediately below the cementoenamel junction. The color alterations (ΔE) were calculated using Commission International de I’Eclairage (CIE) L*a*b parameters, and data were analyzed by analysis of variance (ANOVA) and Tukey’s test (p<0.05). Results: All sealers induced color alterations. Sealer 26 resulted in the smallest changes in color (E = 5.32). The other materials did not present statistical differences (AH Plus E = 6.98; MTA Fillapex E = 6.88; Endofill E = 6.41). Of the three regions analyzed, the largest discoloration was observed at the cervical third of the root (E=10.67). In terms of time, the largest ΔE values (E=7.72) were observed at T4. Color changes at T1 (E=5.88), T2 (E=6.10), and T3 (E=5.89) were statistically similar. Conclusions: All endodontic sealers promoted discoloration on the tooth crown and root.

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Wire Electrodes Embedded in Artificial Conduit for Long-term Monitoring of the Peripheral Nerve Signal

Micromachines ◽

10.3390/mi10030184 ◽

2019 ◽

Vol 10 (3) ◽

pp. 184 ◽

Cited By ~ 2

Author(s):

Woohyun Jung ◽

Sunyoung Jung ◽

Ockchul Kim ◽

HyungDal Park ◽

Wonsuk Choi ◽

...

Keyword(s):

Sciatic Nerve ◽

Peripheral Nerve ◽

Axon Regeneration ◽

Scar Formation ◽

Tissue Response ◽

Nerve Signal ◽

Long Term Monitoring ◽

The Wire ◽

Term Monitoring

Massive efforts to develop neural interfaces have been made for controlling prosthetic limbs according to the will of the patient, with the ultimate goal being long-term implantation. One of the major struggles is that the electrode’s performance degrades over time due to scar formation. Herein, we have developed peripheral nerve electrodes with a cone-shaped flexible artificial conduit capable of protecting wire electrodes from scar formation. The wire electrodes, which are composed of biocompatible alloy materials, were embedded in the conduit where the inside was filled with collagen to allow the damaged nerves to regenerate into the conduit and interface with the wire electrodes. After implanting the wire electrodes into the sciatic nerve of a rat, we successfully recorded the peripheral neural signals while providing mechanical stimulation. Remarkably, we observed the external stimuli-induced nerve signals at 19 weeks after implantation. This is possibly due to axon regeneration inside our platform. To verify the tissue response of our electrodes to the sciatic nerve, we performed immunohistochemistry (IHC) and observed axon regeneration without scar tissue forming inside the conduit. Thus, our strategy has proven that our neural interface can play a significant role in the long-term monitoring of the peripheral nerve signal.

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Wound healing of apical tissues after root canal therapy: a long-term clinical, radiographic, and histopathologic observation study

Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontology ◽

10.1016/j.tripleo.2009.05.028 ◽

2009 ◽

Vol 108 (4) ◽

pp. 609-621 ◽

Cited By ~ 50

Author(s):

Domenico Ricucci ◽

Louis M. Lin ◽

Larz S.W. Spångberg

Keyword(s):

Wound Healing ◽

Root Canal ◽

Observation Study ◽

Root Canal Therapy

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The effect of chlorhexidine and dimethyl sulfoxide on long-term sealing ability of two calcium silicate cements in root canal

Dental Materials ◽

10.1016/j.dental.2020.11.031 ◽

2020 ◽

Author(s):

R.M. Lindblad ◽

L.V.J. Lassila ◽

P.K. Vallittu ◽

L. Tjäderhane

Keyword(s):

Dimethyl Sulfoxide ◽

Root Canal ◽

Calcium Silicate ◽

Sealing Ability ◽

Calcium Silicate Cements

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Effect of Chlorhexidine Treatment Prior to Fiber Post Cementation on Long-Term Resin Cement Bond Strength

Operative Dentistry ◽

10.2341/16-241-lr2 ◽

2018 ◽

Vol 43 (2) ◽

pp. E72-E80 ◽

Cited By ~ 1

Author(s):

M Durski ◽

M Metz ◽

G Crim ◽

S Hass ◽

R Mazur ◽

...

Keyword(s):

Bond Strength ◽

Root Canal ◽

Vertical Axis ◽

Resin Cement ◽

Fiber Post ◽

Resin Cements ◽

Single Root ◽

Number Of Cycles ◽

Push Out

SUMMARY The purpose of this study was to evaluate the push-out bond strength of two different adhesive cements (total etch and self-adhesive) for glass fiber post (GFP) cementation in simulated, long-term service (thermocycling) when the root canal is treated with chlorhexidine before cementation. One hundred twenty premolar specimens with a single root canal were selected, endodontically treated, and shaped for GFP cementation (n=120). The specimens were randomly placed into one of 12 groups (10 specimens each) according to cement (T = total-etch RelyX ARC or S = self-adhesive RelyX Unicem), treatment with chlorhexidine (N or Y: without or with), and number of thermal cycles (00, 20, or 40: 0, or 20,000 or 40,000 cycles): 1. TN00, 2. TN20, 3. TN40, 4. TY00, 5. TY20, 6. TY40, 7. SN00, 8. SN20, 9. SN40, 10. SY00, 11. SY20, 12. SY40. The root of each specimen was cut perpendicular to the vertical axis, yielding six 1.0 mm-thick sections. A push-out bond strength test was performed followed by statistical analysis using a factorial analysis of variance. Pairwise comparisons of significant factor interactions were adjusted using the Tukey test. Significant differences of push-out bond strengths were found in the four main effects (resin cement [p<0.0001], treatment with chlorhexidine [p<0.0001], number of cycles [p<0.0001], and root third [p<0.0001]) and all interactions (p<0.05 for all). Both resin cements produced higher bond strength in the cervical third followed by the middle third, and lower values were detected in the apical third. Additionally, the results suggest that the use of an additional disinfection treatment with chlorhexidine before the cement application produced the highest push-out bond strength regardless of root third. Further, the thermocycling simulation decreased the bond strength for both resin cements long-term when the chlorhexidine was not applied before cementation. However, when the root canal was treated with chlorhexidine and the fiber post was cemented with self-adhesive cement, the bond strength increased after 0, 20,000 and 40,000 cycles.

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