OBJECTIVES OF ROOT CANAL OBTURATION
The objective of the obturation phase of endodontic treatment is to prevent reinfection of root canals that have been shaped and disinfected by instrumentation and irrigation procedures. This also implies that an adequate coronal filling (restoration) will be placed to prevent oral bacterial microleakage from the oral cavity. It has been shown that endodontic treatment success is dependent both on the quality of the obturation and the final restoration.
Sundqvist & Figdor assigned three primary functions to the root filling:
► to prevent coronal leakage which means sealing against ingrowth of bacteria from the oral cavity;
► to entomb miroorganisms which remain and survive after canal instrumentation and rinsing;
► to seal root canal at all levels, especially at the apical area to prevent stagnant fluid from migration into the root canal and giving a nutrient media for bacteria from any source.
ENDODONTIC TERMINOLOGY
Root canal filling means root canal obturation (when we are talking about root canal we can use both words, filling and obturation with the meaning placement of a material into a root canal. BUT when we are talking about tooth restoration, we never use the word obturation but only filling).
There are a lot of obturation techniques in dentistry, only some of them will be discussed below, namely:
1) single paste technique;
2) single cone technique;
3) lateral condensation technique;
4) carrier based gutta-percha technique;
5) vertical condensation technique.
SINGLE PASTE TECHNIQUE
In most dental offices this method is not longer used for permanent obturation of root canals and is considered to be outdated. Its main principle is filling the root canal with one paste (sealer): zinc phosphate cement, zinc-eugenol cement or another cement. Its main disadvantage is poor sealing of root canal and a high risk of microleakage. This method is used nowadays for a temporary filling of root canal (intracanal medication/dressing).