Quantification of endotoxins in infected root canals and acute apical abscess exudates: monitoring the effectiveness of root canal procedures in the reduction of endotoxins.
BACKGROUND
This clinical study was conducted to measure the endotoxin levels in infected root canals (RCs) and exudates related to acute apical abscesses (AAAs). In addition, the effectiveness of RC procedures in reducing the endotoxin levels in RCs was monitored.


METHODS
Paired samples of infected RCs and exudates from AAAs were collected from 10 subjects by using paper points. RCs samples were collected before (RCS1) and after chemomechanical preparation (CMP) (RCS2), after 17% EDTA (RCS3), and after 30 days of intracanal medication (Ca[OH]2 + chlorhexidine) (RCS4). A turbidimetric kinetic limulus amebocyte lysate assay was used for the measurement of endotoxins.


RESULTS
Endotoxins were detected in 100% of the baseline samples of AAAs and RCs (RCS1) with median values of 175 EU/mL and 41.5 EU/mL, respectively (P < .05). After CMP (RCS2), endotoxins were reduced to a median value of 0.54 EU/mL (P < .05). Subsequent irrigation with EDTA (RCS3) failed to present a significant effectiveness in reducing the endotoxin levels (median= 0.37 EU/mL) (P = .07). However, intracanal medication for 30 days (RCS4) reduced endotoxins to median values of 0.03 EU/mL (P < .01).


CONCLUSIONS
The present study revealed a strong association between the high levels of endotoxins found in AAAs and RCs collected from the same tooth. Moreover, the effectiveness of CMP in reducing the endotoxin levels from RCs in acute endodontic infection was improved by the use of RC medication.
Department of Semiology and Clinics, Endodontics Division, School of Dentistry, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil; Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School, State University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil.
Ezilmara L R
EL
Sousa
Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School, State University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil; Department of Restorative Dentistry, Endodontics Division, São José dos Campos Dental School, State University of São Paulo-UNESP, São José dos Campos, São Paulo, Brazil.
Frederico C
FC
Martinho
Department of Semiology and Clinics, Endodontics Division, School of Dentistry, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.
Gustavo G
GG
Nascimento
Department of Semiology and Clinics, Endodontics Division, School of Dentistry, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.
Fabio R M
FR
Leite
Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School, State University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil. Electronic address: bpgomes@fop.unicamp.br.
Brenda P F A
BP
Gomes
D002126:Calcium Hydroxide / Q000627:therapeutic use; D002710:Chlorhexidine / Q000627:therapeutic use; D003786:Dental Pulp Cavity / Q000382:microbiology*; D003790:Dental Pulp Necrosis / Q000382:microbiology*; D003907:Dexamethasone / Q000627:therapeutic use; D004338:Drug Combinations; D004492:Edetic Acid / Q000627:therapeutic use; D004731:Endotoxins / Q000032:analysis*; D005122:Exudates and Transudates / Q000737:chemistry; D005500:Follow-Up Studies; D005557:Formaldehyde / Q000627:therapeutic use; D006171:Gutta-Percha / Q000627:therapeutic use; D006801:Humans; D006854:Hydrocortisone / Q000627:therapeutic use; D008033:Limulus Test; D009391:Nephelometry and Turbidimetry / Q000379:methods; D010482:Periapical Abscess / Q000382:microbiology*; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D012388:Root Canal Irrigants / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000379:methods*; D013943:Thymol / Q000031:analogs & derivatives / Q000627:therapeutic use
D004338:Drug Combinations; D004731:Endotoxins; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; C011244:corticosteroid methanetriol mixture; D005557:Formaldehyde; D013943:Thymol; D003907:Dexamethasone; D006171:Gutta-Percha; D004492:Edetic Acid; D002126:Calcium Hydroxide; D002710:Chlorhexidine; D006854:Hydrocortisone
Abscess; chemomechanical preparation; endodontics; endotoxins; intracanal medicament