The latest in endodontic research

root canalKishor Gulabivala explores the latest endodontic research and summarises everything you need to know here.

In vivo evaluation of effect of preoperative ibuprofen on proinflammatory mediators in irreversible pulpitis cases

Authors: Nguyen V, Chen YW, Johnson JD, Paranjpe A

Where published: Journal of Endodontics 2020 Jun 18



Preoperative administration of nonsteroidal anti-inflammatory drugs has been suggested as a method for increasing the efficacy of local anaesthetics and decreasing postoperative pain in symptomatic irreversible pulpitis cases. However, the effects of ibuprofen at the molecular level are still unknown.

Hence, the purpose of this study was to compare the levels of proinflammatory mediators in the dental pulp of teeth with irreversible pulpitis in patients who medicated with preoperative ibuprofen versus those who did not.


Thirty-four patients undergoing conventional root canal treatment for teeth with irreversible pulpitis were selected.

They were randomly assigned into either the ibuprofen or non-ibuprofen group. Four patients undergoing root canal treatment for prosthodontic reasons served as controls.

Patients in the ibuprofen group were instructed to take 600mg of ibuprofen one hour before treatment. Patients in the non-ibuprofen and control groups were asked to avoid analgesics before treatment.

Blood samples obtained from the pulp upon access were tested for levels of prostaglandin E2, tumour necrosis efactor alpha, interleukin (IL)-6, IL-1beta, and interferon gamma using high-sensitivity enzyme-linked immunosorbent assay.

Postoperative pain levels were recorded for the groups. Data for the cytokine levels and postoperative pain were analysed using statistical analysis.


There was a significant decrease in the levels of prostaglandin E2, tumour necrosis factor alpha, IL-6, and interferon gamma in the ibuprofen group compared with the non-ibuprofen group.

No significant differences were noted in the postoperative pain levels between these groups.


The data showed that preoperative ibuprofen significantly decreased the levels of most pro-inflammatory cytokines in the dental pulp. This could possibly help with anaesthesia in irreversible cases.

Inflammatory biomarkers in dentinal fluid as an approach to molecular diagnostic in pulpitis

Authors: Brizuela C, Meza G, Mercade M, Inostroza C, Chaparro A, Bravo I, Briceno C, Hernandez M, Giner L and Ramirez V

Where published: International Endodontic Journal. 2020 Jun 04

Reference: doi:10.1111/iej.13343


To explore a set of inflammatory biomarkers obtained from dentinal fluid (DF) from patients with symptomatic irreversible pulpitis (IP), reversible pulpitis (RP) and normal pulp (NP).


A cross-sectional exploratory study was performed, recruiting 64 patients on the basis of their respective pulp condition. DF samples were obtained from all patients (23, from IP patients; 20, from RP patients; and 21, from NP patients).

Quantification of biomarkers was performed using a Luminex R MAGPIX platform system and multiplex assay kits. The Kruskal Wallis test was used for comparisons with regard to pulp state. A simple logistic regression model and the odds ratio (OR) with a 95% level of confidence (p=0.05) were used to evaluate associations between biomarker levels and pulpal diagnosis.

The performance discrimination of the biomarkers was evaluated through the construction of a receiver operating characteristic (ROC) curve by calculating the area under the curve (AUC) for IP versus RP after logistic regression modelling.

Youden criteria were used to establish cut-off points for biomarkers alone with AUC>70 and p-value<0.05, or estimated probabilities from the multivariable logistic model.


The biomarkers that had significantly higher values in participants with IP versus RP were IL-1alpha, VEGF-alpha and FGFacid (p<0.05). FGF-acid (OR: 12.62; p = 0.0085; CI 95% 1.91-83.29) and VEGF-alpha (OR: 2.61; p = 0.0252; CI 95% 1.13-6.03) were associated with pulp diagnoses of IP versus RP. The AUC-ROC curve for FGF-acid was 0.79.

The model containing FGF-acid, IL-1alpha, IL-6, and TIMP-1 had an AUCROC of 0.92 for IP versus RP with a significant difference from the FGF-acid ROC curve (p = 0.0231).


The study hypothesis stating that both systemic and local risk factors were associated with higher ECR rates was partly confirmed. One systemic (diabetes) and one local (trauma) risk factor were associated with higher ECR rates.

Three-year outcome of patients with persistent pain after root canal treatment

Authors: Daline IH, Nixdorf DR, Law AS, Pileggi R, National Dental Practice- Based Research Network Collaborative Group

Where published: Journal of Endodontics 2020 Mar 11


We measured the long-term outcomes of patients reporting persistent pain six months after root canal treatment (RCT) and assessed the characteristics differing patients with pain chronification from those with pain resolution.


Forty-five patients previously found to have persistent pain six months post-RCT from the National Dental Practice-Based Research Network were approached for a three-year follow-up, and 27 participated in the survey.

The frequency of self-reported pain, its impact on the ability to perform daily activities, and health care use were measured. The differences between patients whose persistent pain continued and those whose pain resolved were assessed.


Five patients met criteria for pain at 3.4 years (range, 3.1-3.9 years) post-RCT, which was moderate in intensity, occurred for about three days in the preceding month, and kept one patient from usual activities.

Additional health care was received by four of five patients whose pain continued compared with seven of 22 patients whose pain resolved.

A longer duration of preoperative pain and higher pain intensity and interference at six months were found among patients with pain chronification. Of 13 patients with specific diagnoses for the persistent pain derived at 65 +/- 41 days (~eight months) post-RCT, 10 improved regardless of the diagnosis or treatment, and 11 had a temporomandibular disorder and/or headache as comorbid diagnoses (6) or causes (6) of the persistent tooth pain.


Progression of persistent post-RCT pain occurred in 19% of patients. The majority (56%) of patients improved without additional interventions.

Both the group that improved and the group that continued to experience pain had a mixture of odontogenic and nonodontogenic aetiologies.

Endodontic considerations of survival rate for auto-transplanted third molars: a nationwide population-based study

Authors: Lin PY, Chiang YC, Hsu LY, Chang HJ, Chi LY

Where published: International Endodontic Journal 2020 Feb 03


To investigate whether the timing of root canal treatment (primary aim) or other endodontic parameters (secondary aim) are associated with the survival probability of auto-transplanted third molars, using a nationwide population-based database.


A total of 1,811 third molars auto-transplanted between 2000 and 2013 met the inclusion criteria and were followed until the end of 2016.

The teeth were classified into three groups on the basis of timing between root canal treatment and the auto-transplantation: preoperative, extraoral, and postoperative treatment groups.

Univariate and multivariate Cox proportional hazards models were used to estimate the association between the timing of root canal treatment and the risk of tooth extraction after auto-transplantation.


Of the 1,811 auto-transplanted third molars, 462 were extracted, yielding a 17-year survival probability of 0.578.

The survival probability of auto-transplanted teeth that received postoperative root fillings after 17 years was 0.583, which was significantly higher than the 0.434 and 0.566 for teeth that received preoperative and extraoral root fillings, respectively (P = 0.0013).

After adjustment for potential confounding factors, teeth that received postoperative root fillings were associated with a significantly lower tooth extraction hazard ratio (HR) compared with those that received extraoral root fillings (adjusted HR, 1.43; 95% confidence interval [CI], 1.14- 1.78) and those that received preoperative RCT (adjusted HR, 2.13; 95% CI, 1.19- 3.82). Furthermore, the use of a rubber dam during postoperative root filling was associated with a significantly lower extraction rate after auto-transplantation (adjusted HR, 0.54; 95% CI, 0.43-0.69).


Postoperative root canal treatment resulted in a significantly lower extraction rate than did preoperative or extraoral root canal treatment among autotransplanted third molars during a mean follow-up period of 8.33 years.

Rubber dam use is recommended during postoperative root canal treatment to improve the outcomes of auto-transplantation.

The incidence of root canal therapy after full-coverage restorations: a 10-year retrospective study

Authors: Yavorek A, Bhagavatula P, Patel K, Szabo A, Ibrahim M

Where published: Journal of Endodontics 2020 Mar 29


The process of restoring a tooth with a crown leaves many opportunities for pulpal irritation.

The objective of this study was to identify and analyse the factors that contribute to the incidence of nonsurgical root canal therapy (NS-RCT) after the delivery of single-unit full-coverage restorations.


Insurance claims from 88,409 crown placements in the Delta Dental of Wisconsin insurance database were analysed from 2008-2017. The Cox regression model was used to analyse the effect of the predictor variables on the survival of the tooth.

Untoward events were defined as NS-RCT, tooth extraction, retreatment of root canal, or apicoectomy as defined by the Code on Dental Procedures and Nomenclature.


Of 88,409 crowns placed, 8.97% were complete metal, 41.4% were all ceramic, and 49.64% were porcelain fused to metal (PFM).

The probability of survival of all teeth with crowns placed was 90.41% after nine years.

NS-RCT was the most common untoward event. PFM crowns exhibited a higher rate of untoward events than complete metal crowns and a lower rate than all-ceramic crowns. Crowns placed on individuals 50 years of age and younger had higher rates of untoward events than those placed on individuals ages 51 years and older.


The risk of endodontic treatment after the placement of crowns is low. This risk increases with the placement of all-ceramic or PFM crowns and as the age of the patient decreases.

Effect of root canal irrigants on the mechanical properties of endodontically treated teeth: a scoping review

Authors: Dotto L, Sarkis Onofre R, Bacchi A, Rocha Pereira GK

Where published: Journal of Endodontics 2020 Mar 05


The aim of this study was to identify through a scoping review whether root canal irrigants influence the mechanical properties of endodontically treated teeth, and which properties could be affected.

The protocol of this study, available online, followed the Joana Briggs Institute guidelines. Reporting was based on PRISMA Extension for Scoping Reviews.


We selected studies written in English. Ones that evaluated the effect of at least one irrigant on the mechanical properties of endodontically treated teeth.

The search and study screening were performed in Pubmed and Scopus databases by two independent researchers.

A descriptive analysis was performed to consider the study design, the characteristics of the irrigants, and the properties tested.


The initial search yielded 608 citations, of which 66 were included.

On the basis of the collected data, the most commonly used solutions were 17% EDTA, 2.5% or 5% sodium hypochlorite, and 2% chlorhexidine, and the most common tested properties were hardness and strength.

Alterations in the modulus of elasticity, stress and strain concentration during preparation, and roughness were also assessed.


The majority of studies corroborated a negative effect of all solutions on the mechanical properties of endodontically treated teeth

Furthermore, increases in the concentration of the solution and in the time of exposure were found to intensify deleterious effects.

However, disinfection of the canal is also a crucial factor in endodontic success. Thus, clinicians should consider these factors. To mitigate the effects without interfering with antibacterial properties, customising the choice of the solution to the case in hand.

Accidental perforations during root canal treatment: an eight-year nationwide perspective on healthcare malpractice claims

Authors: Vehkalahti MM and Swanljung O

Where published: Clinical Oral Investigations 2020 Mar 05


To assess occurrence and its variation over time of serious accidental perforations during endodontic treatment and the fate of perforated teeth by tooth type and characteristics of patients and dentists.


Data, based on patient documents on healthcare malpractice claims, comprised all endodontic injuries (n = 970) verified by the Patient Insurance Centre in Finland in 2002-2006 and 2011-2013.

Two specialists in endodontics scrutinised the documents. Accidental perforations were recorded by location (tooth type, chamber/canals). They were dichotomised as avoidable (could have been avoided by following good clinical practice) or unavoidable (normal treatment-related risks). Fate of perforation cases was recorded as treatment discontinued, root canal(s) filled, or tooth extracted.

Background information included patients’ and dentists’ sex and age and the service sector. Statistical evaluation used Chi-square tests.


Serious accidental perforations comprised 29% of all verified injuries. Most perforations were judged as avoidable: 93% in patients aged below 35 years, 87% when located in the pulp chamber or in molars (84%); 70% of all perforations and 75% of those in molars resulted in tooth extraction.

The overall rate of serious accidental perforations was 17.6 cases per 100,000 endodontic patients per year.


The rate of serious accidental perforations increased over time. The majority was in molars and resulted in tooth extraction.

Accidental perforations comprise almost a third of serious injuries during root canal treatment. However, four of five perforations could be avoided by following good clinical practice.

Therefore, training is needed before adopting new working equipment and methods.

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