Title Immediate Post Space Preparation Leads to Less Micro-leakage in the Root Canal System Compared to Delayed Post Placement
Clinical Question In endodontically treated teeth that require a post-retained restoration, does immediate post space preparation, compared to delayed post preparation, lead to less leakage in the root canal system?
Clinical Bottom Line Based on in vitro studies, immediate post space preparation results in less leakage in endodontically treated teeth obturated with either Gutta-Percha or Resilon and various sealers. Time of post space preparation seems to have an effect on the integrity of the apical seal, regardless of the obturation material.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
24596779Dhaded/201480 maxillary central +lateral incisorsLaboratory study
Key resultsRoot canals were obturated either with Gutta-Percha and AH Plus sealer, or with Resilon and Epiphany sealer. In each group, post space preparation was completed either immediately after obturation or 1 week post-treatment. The study showed significant difference in leakage between immediate and delayed preparation for both Resilon and Gutta-Percha, with immediate showing the least leakage, irrespectively of the filling material. In immediate post space preparation, the aseptic conditions can be easily followed and the condensation of the remaining Gutta-Percha can be addressed and improved, if necessary. Additionally, sealer is not completely set immediately after root canal treatment and its bond to the dentin walls is minimally compromised when immediate post space is prepared. Sealer can still run through and set within the microcracks. In delayed preparation, the Resilon group showed better results than the Gutta-Percha group. Higher tensile strength and setting of the sealer after light curing may allow for better resistance to crumbling during post space preparation. In case of Gutta-Percha, the rotation forces during space preparation may cause the movement of the material, thus breaking the bond of the sealer interface.
20806703Jalalzadeh/201086 single-canal premolar teethLaboratory study
Key resultsRoot canals were obturated with Gutta-Percha and two different sealers were used; AH26 and ZOE Dorifil. Post space was prepared either immediately or with delay, 1 week later, and the teeth were tested for bacterial microleakage at 45 and 70 days. The study detected more microleakage in group where AH26 was used as a sealer and post placement was delayed. During delayed post space preparation, it is likely that burs’ rotation and high temperature cause loss of integrity of the set resin sealer, enough to compromise its adhesion to dentin.
20608304Zmener/201048 teeth, with single straight root canalsLaboratory study
Key resultsRoot canals were obturated with Endorez, with and without accelerator and post space preparation was performed either immediately after obturation or delayed, 7 days later. The study showed significant difference in bacterial leakage between immediate and delayed post space preparation, with the delayed resulting in more pronounced and earlier coronal leakage. Delayed post space preparation may cause damage to the resin tags, leading to disruption of the bond of the sealer/dentin interface of the 5mm remaining apical filling. On the other hand, a better apical seal is maintained during immediate post space preparation, as the polymerization shrinkage stresses have not been fully developed.
Evidence Search Bacterial[All Fields] AND microleakage[All Fields] AND post[All Fields] AND space[All Fields] AND timing[All Fields] OR timing[All Fields] AND (“methods”[MESH TERMS] OR “methods[All Fields] OR “method” [All Fields]) AND post[All Fields] AND space[All Fields] AND leakage[All Fields] AND (“plant roots”[MESH TERMS] OR “plant” [All Fields] AND “roots” [All Fields] OR “plant roots” [All Fields] OR “root” [All Fields]) AND filling[All Fields] AND material[All Fields]
Comments on
The Evidence
Validity: There is a consensus among various in vitro studies regarding the effect of time of post space preparation on the apical seal. However, the level of evidence is low as there are no clinical studies reported in the literature. Nevertheless, the available evidence clearly shows that immediate post preparation may lead to less amount of leakage and better integrity of the apical seal. Perspective: While the available evidence supports the immediate post space preparation, the integrity of the apical seal is multifactorial and depends on several variables, such as obturation technique, length of Gutta-Percha maintaining the apical seal, filling materials, types of sealers, methods of Gutta-Percha removal.
Applicability Based on the available evidence, the aim for the clinicians would be to prepare the post space immediately after root canal treatment.
Specialty (Endodontics) (General Dentistry) (Prosthodontics) (Restorative Dentistry)
Keywords Post and core, Immediate vs Delayed post preparation
ID# 2773
Date of submission 11/18/2014
E-mail gerogianni@uthscsa.edu
Author Petrina Gerogianni, DDS
Co-author(s) e-mail
Faculty mentor Vanessa Chrepa, BDS
Faculty mentor e-mail chrepa@uthscsa.edu
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
Comments and Evidence-Based Updates on the CAT
None available