Influence of apical patency and cleaning of the apical foramen on periapical extrusion in retreatment.
This study evaluated the influence of apical patency, root filling removal technique and cleaning of the apical foramen, concerning the amount of debris extruded during root canal retreatment. Forty mandibular incisors were randomly assigned to 4 groups - GIM (n=10), GIIM (n=10), GIPT (n=10) and GIIPT (n=10), which were named according to leaving (I) or not (II) apical patency during canal preparation and filling removal technique (manual - M or ProTaper system - PT). After filling material removal, each specimen of each group had the apical foramen cleaned by sizes 15, 20 and 25 instruments, generating 12 subgroups: GIM15, GIM20, GIM25, GIIM15, GIIM20, GIIM25, GIPT15, GIPT20, GIPT25, GIIPT15, GIIPT20 and GIIPT25. Extruded filling debris was collected by a Milipore filtration system, an HV-durapore, 0.45 µm pore filter with a 25 mm diameter. The filters were weighed before and after the collection on an analytical scale (10-5 g), and the difference was calculated. The mean weight of extruded filling debris was analyzed statistically by Kruskal-Wallis and Friedman ANOVA tests (α=0.05). The mean values found in the groups (in mg) were: GIM (0.95 ± 0.94), GIIM (0.47 ± 0.62), GIPT (0.30 ± 0.31) and GIIPT (0.32 ± 0.44). There was no statistically significant difference among any of the groups or subgroups (p>0.05). ProTaper provided the smallest amount of extruded filling material, regardless of presence or absence of apical patency, followed by manual technique, without and with apical patency. Additional amounts of debris were collected during cleaning of the apical foramen, regardless of the instrument, presence/absence of patency or root filling removal technique.
Department of Endodontics, UFPR - Federal University of Paraná, CuritibaPR, Brazil.
Marili Doro Andrade
MD
Deonizio
Department of Endodontics, UFPR - Federal University of Paraná, CuritibaPR, Brazil.
Gilson Blitzkow
GB
Sydney
Department of Endodontics, UFPR - Federal University of Paraná, CuritibaPR, Brazil.
Antonio
A
Batista
Department of Pharmacy, UFPR - Federal University of Paraná, CuritibaPR, Brazil.
Roberto
R
Pontarolo
Department of Statistics, UFPR - Federal University of Paraná, CuritibaPR, Brazil.
Paulo Ricardo Bittencourt
PR
Guimarães
Department of Esthetic Dentistry, School of Dentistry, USP - University of São Paulo, SP, Brazil.
Giulio
G
Gavini
D006801:Humans; D012387:Root Canal Filling Materials; D018915:Root Canal Preparation / Q000379:methods*; D019227:Tooth Apex / Q000502:physiology*
D012387:Root Canal Filling Materials