Effect of timing of post space preparation on the apical seal when using different sealers and obturation techniques

Quality of post and core placement by final year undergraduate dental students

The success of endodontic restoration of badly compromised teeth depends on the quality of post and core placement and the extra-coronal restoration. Ensuring that students place posts to acceptable quality standards is therefore essential. The aim of this study was to radiographically evaluate post placement by final year undergraduate dental students and to identify any predictors of performance. Two hundred retrospectively and randomly selected posts placed by sixth year students were evaluated radiographically. Data on student gender; number and quality of radiographs; periapical pathology; tooth location; root canal treatment quality; amount of remaining gutta percha; gap between gutta percha and post; post-to-root width; crown-to-root ratio; and types of core material and crowns were recorded. Four criteria were used to grade post placement quality: (i) amount of remaining gutta percha; (ii) gap between gutta percha and post; (iii) post width to root ratio; and (iv) crown-to-root ratio. Assessments were scored to produce final grades. Data are presented using descriptive statistics and the chi-squared test was used to investigate whether student gender or tooth location were associated with final grade. Post and core quality was acceptable in most cases (97.5% were graded as adequate), with no differences in quality between male and female students nor according to tooth location (anterior, premolar, and molar). Just over half of radiographs were adequate quality (53.5%), while just under half were assessed as less than adequate (46.5%) due to cone cutting, overlap, shortening or elongation, although this did not affect formal assessment of post quality. General outcomes of post and core placement by undergraduate students were good, with few errors that might affect the prognosis and long-term survival of treated teeth. Providing undergraduate dental students with clear guidelines on when and how to take radiographs throughout the procedure may improve the quality of post and core treatment and reduce the risk of multiple unnecessary radiographic exposures. From the clinical perspective, although dental students generally place high quality posts and cores, it remains important to monitor the quality and performance of post placement as this determines the survival of compromised teeth.

Immediate and Delayed Post Space Preparations in Endodontically Treated Teeth: A Scoping Review

BACKGROUND

The aim of the present review was to identify the effect of the post-space preparation (PSP) timing (immediate or delayed) on endodontically treated teeth.

METHODS

All studies in any language that compared the effect of immediate versus delayed PSP on the outcomes of an endodontically treated tooth were searched in PubMed, Scopus, Web of Science, Cochrane, ProQuest, WorldCat, and Google Scholar databases by two independent researchers until February 12, 2022. Studies assessing merely the immediate or delayed PSP were excluded. A descriptive analysis was performed to evaluate the study design and the characteristics of the included studies.

RESULTS

The initial search yielded 2612 records, of which 68 were included. Except for one randomized controlled trial, all were in vitro. The evaluated variables were apical/coronal microleakage (n = 48/n = 1), post-bond strength (n = 8), bacterial infiltration (n = 7), presence of voids (n = 3), apical extrusion and residual of filling material (n = 1), and post-operative pain (n = 1). The number of publications had steady growth per year and fast growth per decade. "Post-space preparation" was the most popular keywords.

CONCLUSIONS

The present review highlights the need for further investigations due to the various design of studies, controversial results, and an inadequate number of randomized controlled trials.

TRIAL REGISTRATION

Retrospectively registered. Open Science ( https://doi.org/10.17605/OSF.IO/2YTM6 ).

Comparison of the effect of post space preparation time on the apical seal of two different sealers

BACKGROUND

The present study compared the effect of post space preparation time on the apical seal of two different sealers.

METHODS

In the in vitro study, 94 central incisors were used. After the samples' root canal preparation, they were randomly assigned to four experimental groups (n = 21). The samples in groups 1 and 2 were obturated with AH Plus sealer, gutta-percha, and in groups 3 and 4 with Endoseal MTA bioceramic sealer and single cone technique. The post spaces in groups 1 and 3 were prepared immediately and in groups 2 and 4 with a delay. The samples were evaluated at 7-, 30-, and 90-day intervals for apical microleakage using the fluid filtration technique. The data were analyzed with SPSS 25, using three-way ANOVA and independent t-test.

RESULTS

The apical microleakage in groups 3 and 4, obturated with Endoseal MTA bioceramic sealer and prepared immediately and after a delay, respectively, was not significantly different between the interval times. In group 2, obturated with AH Plus sealer and prepared for post space with a delay, the apical microleakage was significantly less than all the other groups. Group 1, obturated with AH Plus sealer and prepared for post space immediately, exhibited the least microleakage after seven days, but its microleakage increased over time to reach the level of groups 3 and 4.

CONCLUSION

According to the results, the apical microleakage in the AH + sealer group and the delayed post-space preparation method, was significantly less than all the other groups over time.

Bacterial microleakage in endodontically treated teeth following two methods of postspace preparation at two-time intervals: An in vitro study

Aims

The goal of this study was to analyze the bacterial microleakage following two methods (heat vs. rotary) of postspace preparation after two-time intervals (immediate vs. 1 week later).

Setting and Design

In vitro-comparative study.

Materials and Methods

Eighty-two single-rooted teeth were decoronated at the cementoenamel junction. Root canals were prepared using rotary files. After root canal obturation, specimens were randomly allocated to 4 experimental groups based on the method of postspace preparation (heat or peeso reamer) and time interval (immediate or 1 week later) (n = 18). Group 1: Peeso reamer-immediate, Group 2: Heat-immediate, Group 3: Peeso reamer-1 week later, Group 4: Heat-1 week later. 10 specimens were considered as positive and negative controls (n = 5 each). Custom-made dual-chamber devices were used to appraise the bacterial microleakage for 60 days.

Statistical Analysis Used

Data were analyzed with Chi-Square and Log-Rank tests and Cox regression.

Results

All through the experimental period, there was no significant difference (P = 0.41) between the studied groups. Groups 2 and 4 had the highest microleakage and the lowest survival rate (55.56% ± 11.71%). Group 1 showed the lowest microleakage and the highest survival rate (77.8% ± 9.80%).

Conclusions

The applied techniques for postspace preparation and the time intervals (neither independently nor simultaneously) showed no significant difference in the field of bacterial leakage.

Evaluation of apical leakage after immediate and delayed postspace preparation using different root canal sealers: An in vitro study

Background

Endodontically treated teeth with extensive loss of tooth structure lacks sufficient support for a permanent restoration. While restoring them with post and core it is important not to disrupt the apical seal.

Aim

Evaluation of apical leakage after immediate and delayed postspace preparation using two root canal sealers.

Materials and Methods

Sixty single-rooted teeth were decoronated and roots were biomechanically prepared and obturated with gutta-percha and 2 sealers: AH Plus (Group A, n = 30) and Sure-Seal root canal sealer (Group B, n = 30). Groups A and B were subdivided into A1, A2 and B1, B2. Postspace was prepared immediately for A1 and B1. For A2 and B2 post space was prepared after storage in physiologic saline for 1 week. The samples were kept in Rhodamine B dye for 72 h and then sectioned longitudinally to observe dye penetration along the root canal wall under Stereomicroscope. The dye penetration was measured linearly and the values were subjected for statistical analysis using one-way analysis of variance and t-test.

Results

Statistically significant difference between Group A (1.00 mm) and B (2.71 mm) was observed (P < 0.001). However, the subgroups for immediate and delayed post space preparation did not show statistically significant difference (A1 = 0.947; A2 = 1.043; B1 = 2.306 and B2 = 3.120, P < 0.001).

Conclusion

AH plus sealer showed lesser leakage compared to Sure-Seal Root canal sealer. The difference in leakage values was not statistically significant in delayed and immediate post space preparation groups, Time of postspace preparation has no influence on apical leakage.

Comparison between immediate and delayed post space preparations: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis compared the effects of immediate and delayed post space preparation on apical sealing.

MATERIALS AND METHOD

Two independent authors conducted a systematic search (PubMed/Medline, Cochrane Library, and other databases, until February 2020) and a risk of bias evaluation. Only in vitro studies that compared the effects of immediate and delayed post space preparations on apical filling and adhesion of the post were eligible.

RESULT

Of the 742 articles retrieved, 32 were included. Most of the studies used single-rooted human teeth and rotary files for root canal preparation, a single-cone technique for the filling protocol, and rotary instruments for post space preparation. Various delayed preparation times were evaluated: 8-72 h, 5-30 days (mainly 7 days), and 4 months. In nine studies, the delayed groups showed more apical leakage, while four studies reported more leakage in the immediate groups; ten studies found no significant difference. One study found more bacterial penetration in the delayed group, whereas three studies showed no significant difference. One study reported more voids in the delayed group, while another found no such difference. Three studies showed better post-bond strength in the delayed group, one in the immediate group, whereas three found no significant difference in post-bond strength. Three studies employing varied sealers for root canal fillings were considered for meta-analysis. Two subgroup analyses were also performed (one concerning the use of resin-based sealers (AH Plus), another for zinc oxide-eugenol-based sealers). The results of the meta-analysis showed that a delayed post space preparation led to a significantly higher apical leakage than an immediate preparation (mean difference = 0.41 mm, confidence interval = 0.24-0.59, p < 0.001).

CONCLUSION

Delayed post space preparation seems to negatively influence apical sealing; however, further studies are needed to determine the influence of the timing of post space preparation on the other parameters.

CLINICAL RELEVANCE

Immediate post space preparation may be the safest clinical choice to prevent apical leakage.

Post space preparation timing of root canals sealed with AH Plus sealer

OBJECTIVES

To determine the optimal timing for post space preparation of root canals sealed with epoxy resin-based AH Plus sealer in terms of its polymerization and influence on apical leakage.

MATERIALS AND METHODS

The epoxy polymerization of AH Plus (Dentsply DeTrey) as a function of time after mixing (8, 24, and 72 hours, and 1 week) was evaluated using Fourier transform infrared (FTIR) spectroscopy and microhardness measurements. The change in the glass transition temperature (Tg ) of the material with time was also investigated using differential scanning calorimetry (DSC). Fifty extracted human single-rooted premolars were filled with gutta-percha and AH Plus, and randomly separated into five groups (n = 10) based on post space preparation timing (immediately after root canal obturation and 8, 24, and 72 hours, and 1 week after root canal obturation). The extent of apical leakage (mm) of the five groups was compared using a dye leakage test. Each dataset was statistically analyzed by one-way analysis of variance and Tukey's post hoc test (α = 0.05).

RESULTS

Continuous epoxy polymerization of the material with time was observed. Although the Tg values of the material gradually increased with time, the specimens presented no clear Tg value at 1 week after mixing. When the post space was prepared 1 week after root canal obturation, the leakage was significantly higher than in the other groups (p < 0.05), among which there was no significant difference in leakage.

CONCLUSIONS

Poor apical seal was detected when post space preparation was delayed until 1 week after root canal obturation.