Effect of apical constriction diameter, irrigant flow rate, and needle tip design on apical pressure
10.14815/kjdm.2019.46.2.75
- Author:
Chang Ha LEE
1
;
Seol Ah JO
;
Bum Soon LIM
;
In Bog LEE
Author Information
1. Department of Conservative Dentistry, School of Dentistry, Seoul National University, Seoul, Korea. inboglee@snu.ac.kr
- Publication Type:Original Article
- Keywords:
Apical constriction diameter;
Apical pressure;
Irrigant flow rate;
Needle tip design
- MeSH:
Bicuspid;
Central Venous Pressure;
Constriction;
Dental Pulp Cavity;
Humans;
Needles;
Tooth;
Tooth Apex
- From:
Korean Journal of Dental Materials
2019;46(2):75-88
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
The purpose of this study was to evaluate the effects of apical constriction (AC) diameter, irrigant flow rate, and needle tip design on apical pressure (AP) during the root canal irrigation. Five extracted human mandibular premolars were instrumented up to #35 (0.06 taper) using nickel-titanium rotary instruments. AC was determined at 1 mm from the apical foramen. Three needles with different tip designs (notched, side-vented, and flat) were placed 3 mm from AC. APs were measured with varying flow rates of 0.05, 0.1, 0.2, and 0.3 mL/s. The AC diameter of the teeth was enlarged to #40 and #45 (0.06 taper) successively, and the aforementioned measurement procedure was repeated (n=5). When the other conditions were controlled, AP increased with decreasing AC diameter or increasing irrigant flow rate, and the AP of flat needle was the highest, followed by notched, and side-vented needle (p<0.05). The APs with 0.05 mL/s flow rate were lower than central venous pressure (5.88 mmHg) for all conditions. Under the conditions of the present study, flat needle is not recommended in narrow AC (0.35 mm), as the value of the AP with a flow rate of 0.05 mL/s is similar to the central venous pressure. However, in AC diameter of >0.35 mm, open-end (notched or flat) needles can be used to improve irrigant replacement in the apical portion using a flow rate of 0.05 mL/s.
