Frequency of persistent tooth pain after root canal therapy: a systematic review and meta-analysis

Critical Assessment of Search Strategies in Systematic Reviews in Endodontics

INTRODUCTION

The aim of this study was to perform an overview of literature search strategies in systematic reviews (SRs) published in 2 endodontic journals, Journal of Endodontics and International Endodontic Journal.

METHODS

A search was done by using the MEDLINE (PubMed interface) database to retrieve the articles published between January 1, 2000 and December 31, 2015. The last search was on January 10, 2016. All the SRs published in the 2 journals were retrieved and screened. Eligible SRs were assessed by using 11 questions about search strategies in the SRs that were adapted from 2 guidelines (ie, AMSTAR checklist and the Cochrane Handbook).

RESULTS

A total of 83 SRs were retrieved by electronic search. Of these, 55 were from the Journal of Endodontics, and 28 were from the International Endodontic Journal. After screening, 2 SRs were excluded, and 81 SRs were included in the study. Some issues, such as search of grey literature and contact with study authors, were not fully reported (30% and 25%, respectively). On the other hand, some issues, such as the use of index terms and key words and search in at least 2 databases, were reported in most of the SRs (97% and 95%, respectively). The overall quality of the search strategy in both journals was 61%. No significant difference was found between the 2 journals in terms of evaluation criteria (P > .05).

CONCLUSIONS

There exist areas for improving the quality of reporting of search strategies in SRs; for example, grey literature should be searched for unpublished studies, no language limitation should be applied to databases, and authors should make an attempt to contact the authors of included studies to obtain further relevant information.

Comparison of Single Visit Post Endodontic Pain Using Mtwo Rotary and Hand K-File Instruments: A Randomized Clinical Trial

OBJECTIVES

Pain is an unpleasant outcome of endodontic treatment that can be unbearable to patients. Instrumentation techniques may affect the frequency and intensity of post-endodontic pain. This study aimed to compare single visit post endodontic pain using Mtwo (NiTi) rotary and hand K-file instruments.

MATERIALS AND METHODS

In this randomized controlled trial, 60 teeth with symptomatic irreversible pulpitis in 53 patients were selected and randomly assigned into two groups of 30 teeth. In group A, the root canals were prepared with Mtwo (NiTi) rotary instruments. In group B, the root canals were prepared with hand K-file instruments. Pain assessment was implemented using visual analog scale (VAS) at four, eight, 12 and 24 hours after treatment. The acquired data were analyzed using chi-square, Mann-Whitney U and Student's t-test (P<0.05).

RESULTS

Patients treated with rotary instruments experienced significantly less post-endodontic pain than those treated with hand instruments (P<0.001).

CONCLUSIONS

The use of Mtwo (NiTi) rotary instruments in root canal preparation contributed to lower incidence of postoperative pain than hand K-files.

Altered pain modulation in patients with persistent postendodontic pain

Persistent pain may follow nerve injuries associated with invasive therapeutic interventions. About 3% to 7% of the patients remain with chronic pain after endodontic treatment, and these are described as suffering from painful posttraumatic trigeminal neuropathy (PTTN). Unfortunately, we are unable to identify which patients undergoing such procedures are at increased risk of developing PTTN. Recent findings suggest that impaired endogenous analgesia may be associated with the development of postsurgical chronic pain. We hypothesized that patients with PTTN display pronociceptive pain modulation, in line with other chronic pain disorders. Dynamic (conditioned pain modulation, temporal summation) and static (response to mechanical and cold stimulation) psychophysical tests were performed intraorally and in the forearm of 27 patients with PTTN and 27 sex- and age-matched controls. The dynamic sensory testing demonstrated less efficient conditioned pain modulation, suggesting reduced function of the inhibitory endogenous pain-modulatory system, in patients with PTTN, mainly in those suffering from the condition for more than a year. The static sensory testing of patients with PTTN demonstrated forearm hyperalgesia to mechanical stimulation mainly in patients suffering from the condition for less than a year and prolonged painful sensation after intraoral cold stimulus mainly in patients suffering from the condition for more than a year. These findings suggest that PTTN is associated more with the inhibitory rather than the facilitatory arm of pain modulation and that the central nervous system has a role in PTTN pathophysiology, possibly in a time-dependent fashion.

Effect of maintaining apical patency on endodontic pain in posterior teeth with pulp necrosis and apical periodontitis: a randomized controlled trial

AIM

To evaluate the association between apical patency and post-operative pain in posterior teeth with pulp necrosis and apical periodontitis.

METHODOLOGY

Sixty-eight patients requiring primary root canal treatment in mandibular first molars with necrotic pulps and apical periodontitis were included. The patients were randomly allocated to one of two groups: patency (n = 34) and nonpatency (n = 34). After administering local anaesthesia, root canal preparation was completed using ProTaper rotary instruments. A size 10 K-file was used as a patency file and carried 1 mm beyond the working length (WL) between each instrument change in the patency group, while it was carried up to WL in the nonpatency group. Patients were asked to record their pain experience on a pain chart daily for 7 days. Three patients (two in the patency group, one in the nonpatency group) did not return with completed pain charts on the subsequent visit, resulting in a total of 65 patients for the final analysis (patency, n = 32; nonpatency, n = 33). Data was analysed using Chi Square test, t-test, Mann-Whitney test and Wilcoxon Signed Ranks test.

RESULTS

Overall, 43% of the patients experienced post-operative pain. The patency group had less incidence of pain (34%) as compared to the nonpatency group (52%), but the difference was not significant (P = 0.163).

CONCLUSION

Maintenance of apical patency during chemomechanical preparation had no significant influence on post-operative pain in posterior teeth with necrotic pulps and apical periodontitis.

Differential diagnoses for persistent pain after root canal treatment: a study in the National Dental Practice-based Research Network

INTRODUCTION

Pain present 6 months after root canal treatment (RCT) may be of odontogenic or nonodontogenic origin. This is important because treatments and prognoses are different; therefore, the aim of this study was to provide specific diagnoses of patients reporting pain 6 months after receiving initial orthograde RCT.

METHODS

We enrolled patients from the Midwest region of an existing prospective observational study of pain after RCT. Pain at 6 months was defined as ≥1 day of pain and average pain intensity of at least 1 of 10 over the preceding month. An endodontist and an orofacial pain practitioner independently performed clinical evaluations, which included periapical and cone-beam computed tomographic radiographs, to determine diagnoses.

RESULTS

Thirty-eight of the 354 eligible patients in the geographic area (11%) met the pain criteria, with 19 (50%) consenting to be clinically evaluated. As the sole reason for pain, 7 patients (37%) were given odontogenic diagnoses (4 involving the RCT tooth and 3 involving an adjacent tooth). Eight patients (42%) were given nonodontogenic pain diagnoses (7 from referred temporomandibular disorder pain and 1 from persistent dentoalveolar pain disorder). Two patients (11%) had both odontogenic and nonodontogenic diagnoses, whereas 2 (11%) no longer fit the pain criteria at the time of the clinical evaluation.

CONCLUSIONS

Patients reporting "tooth" pain 6 months after RCT had a nonodontogenic pain diagnosis accounting for some of this pain, with temporomandibular disorder being the most frequent nonodontogenic diagnosis. Dentists should have the necessary knowledge to differentiate between these diagnoses to adequately manage their patients.

Root Canal Penetration of a Sodium Hypochlorite Mixture Using Sonic or Ultrasonic Activation

The purpose of this ex vivo study was to determine, in "open" and "closed" systems, whether the design has an influence on the penetration length of sodium hypochlorite mixed with a radiopaque contrast medium, measured in millimeters, when delivered using positive pressure (PP) and using sonic (SI) or passive ultrasonic (PUI) activation. Sixty single-rooted teeth were divided into two groups: open and closed systems (n=30). Root canal shaping was performed to a working length of 17 mm. The samples were divided into three sub-groups (n=10) according to irrigant delivery and activation: PP, and SI or PUI activation. By using radiographs, penetration length was measured, and vapor lock was assessed. For the closed group, the penetration distance means were: PP 15.715 (±0.898) mm, SI 16.299 (±0.738) mm and PUI 16.813 (±0.465) mm, with vapor lock occurring in 53.3% of the specimens. In the open group, penetration to 17 mm occurred in 97.6% of the samples, and no vapor lock occurred. Irrigant penetration and distribution evaluation using open and closed systems provide significantly different results. For closed systems, PUI is the most effective in delivering the irrigant to working length, followed by SI.

Prevalence of persistent pain 3 to 5 years post primary root canal therapy and its impact on oral health-related quality of life: PEARL Network findings

INTRODUCTION

The frequency of persistent pain 3-5 years after primary root canal therapy and its impact on the patient's perceived oral health-related quality of life was determined in a practice-based research network.

METHODS

All patients presenting to participating network practices who received primary root canal therapy and restoration for a permanent tooth 3-5 years previously were invited to enroll. Persistent pain was defined as pain occurring spontaneously or elicited by percussion, palpation, or biting. The patient also completed an oral health-related quality of life questionnaire (Oral Health Impact Profile-14).

RESULTS

Sixty-four network practices enrolled 1323 patients; 13 were ineligible, 12 did not receive a final restoration, and 41 were extracted, leaving 1257 for analysis. The average time to follow-up was 3.9 ± 0.6 years. Five percent (63/1257) of the patients reported persistent pain, whereas 24 of 63 (38%) exhibited periapical pathosis and/or root fracture (odontogenic pain). No obvious odontogenic cause for persistent pain was found for 39 of 63 (62%). Teeth treated by specialists had a greater frequency of persistent pain than teeth treated by generalists (9.3% vs 3.0%, respectively; P < .0001). Sex, age, tooth type, type of dentist, and arch were not found to be associated with nonodontogenic persistent pain; however, ethnicity and a preoperative diagnosis of pulpitis without periapical pathosis were. Patients reporting pain with percussion tended to experience pain with other stimuli that negatively impacted quality of life including oral function and psychological discomfort and disability.

CONCLUSIONS

These results suggest that a small percentage (3.1%) of patients experience persistent pain not attributable to odontogenic causes 3-5 years after primary root canal therapy that may adversely impact their quality of life.

Healthcare outcomes assessed with observational study designs compared with those assessed in randomized trials

BACKGROUND

Researchers and organizations often use evidence from randomized controlled trials (RCTs) to determine the efficacy of a treatment or intervention under ideal conditions. Studies of observational designs are often used to measure the effectiveness of an intervention in 'real world' scenarios. Numerous study designs and modifications of existing designs, including both randomized and observational, are used for comparative effectiveness research in an attempt to give an unbiased estimate of whether one treatment is more effective or safer than another for a particular population.A systematic analysis of study design features, risk of bias, parameter interpretation, and effect size for all types of randomized and non-experimental observational studies is needed to identify specific differences in design types and potential biases. This review summarizes the results of methodological reviews that compare the outcomes of observational studies with randomized trials addressing the same question, as well as methodological reviews that compare the outcomes of different types of observational studies.

OBJECTIVES

To assess the impact of study design (including RCTs versus observational study designs) on the effect measures estimated.To explore methodological variables that might explain any differences identified.To identify gaps in the existing research comparing study designs.

SEARCH METHODS

We searched seven electronic databases, from January 1990 to December 2013.Along with MeSH terms and relevant keywords, we used the sensitivity-specificity balanced version of a validated strategy to identify reviews in PubMed, augmented with one term ("review" in article titles) so that it better targeted narrative reviews. No language restrictions were applied.

SELECTION CRITERIA

We examined systematic reviews that were designed as methodological reviews to compare quantitative effect size estimates measuring efficacy or effectiveness of interventions tested in trials with those tested in observational studies. Comparisons included RCTs versus observational studies (including retrospective cohorts, prospective cohorts, case-control designs, and cross-sectional designs). Reviews were not eligible if they compared randomized trials with other studies that had used some form of concurrent allocation.

DATA COLLECTION AND ANALYSIS

In general, outcome measures included relative risks or rate ratios (RR), odds ratios (OR), hazard ratios (HR). Using results from observational studies as the reference group, we examined the published estimates to see whether there was a relative larger or smaller effect in the ratio of odds ratios (ROR).Within each identified review, if an estimate comparing results from observational studies with RCTs was not provided, we pooled the estimates for observational studies and RCTs. Then, we estimated the ratio of ratios (risk ratio or odds ratio) for each identified review using observational studies as the reference category. Across all reviews, we synthesized these ratios to get a pooled ROR comparing results from RCTs with results from observational studies.

MAIN RESULTS

Our initial search yielded 4406 unique references. Fifteen reviews met our inclusion criteria; 14 of which were included in the quantitative analysis.The included reviews analyzed data from 1583 meta-analyses that covered 228 different medical conditions. The mean number of included studies per paper was 178 (range 19 to 530).Eleven (73%) reviews had low risk of bias for explicit criteria for study selection, nine (60%) were low risk of bias for investigators' agreement for study selection, five (33%) included a complete sample of studies, seven (47%) assessed the risk of bias of their included studies,Seven (47%) reviews controlled for methodological differences between studies,Eight (53%) reviews controlled for heterogeneity among studies, nine (60%) analyzed similar outcome measures, and four (27%) were judged to be at low risk of reporting bias.Our primary quantitative analysis, including 14 reviews, showed that the pooled ROR comparing effects from RCTs with effects from observational studies was 1.08 (95% confidence interval (CI) 0.96 to 1.22). Of 14 reviews included in this analysis, 11 (79%) found no significant difference between observational studies and RCTs. One review suggested observational studies had larger effects of interest, and two reviews suggested observational studies had smaller effects of interest.Similar to the effect across all included reviews, effects from reviews comparing RCTs with cohort studies had a pooled ROR of 1.04 (95% CI 0.89 to 1.21), with substantial heterogeneity (I(2) = 68%). Three reviews compared effects of RCTs and case-control designs (pooled ROR: 1.11 (95% CI 0.91 to 1.35)).No significant difference in point estimates across heterogeneity, pharmacological intervention, or propensity score adjustment subgroups were noted. No reviews had compared RCTs with observational studies that used two of the most common causal inference methods, instrumental variables and marginal structural models.

AUTHORS' CONCLUSIONS

Our results across all reviews (pooled ROR 1.08) are very similar to results reported by similarly conducted reviews. As such, we have reached similar conclusions; on average, there is little evidence for significant effect estimate differences between observational studies and RCTs, regardless of specific observational study design, heterogeneity, or inclusion of studies of pharmacological interventions. Factors other than study design per se need to be considered when exploring reasons for a lack of agreement between results of RCTs and observational studies. Our results underscore that it is important for review authors to consider not only study design, but the level of heterogeneity in meta-analyses of RCTs or observational studies. A better understanding of how these factors influence study effects might yield estimates reflective of true effectiveness.

Evaluation of mineral trioxide aggregate as root canal sealer: A clinical study

Aim:

The aim of this study was to compare the clinical and radiological outcome of mineral trioxide aggregate (MTA) or epoxy resin as a root canal sealer compared with zinc oxide eugenol sealer.

Materials and Methods:

45 single rooted teeth with periapical index Score 2 or more were allotted to three groups with 15 teeth in each group. Root canal treatment was performed in two visits and obturated with Gutta-percha as obturating material and zinc oxide eugenol as sealer in Group 1, epoxy resin as sealer in Group 2 and MTA mixed with propylene glycol as sealer in Group 3. Visual analog scale, periapical index and VixWin digital Pro image analysis software were used for evaluation. The quantitative data was analyzed by t-test and analysis of variance. Ordinal data was analyzed by Wilcoxon's signed rank test, Mann-Whitney and Kruskall-Wallis test.

Results:

Results suggested that there exists no statistically significant difference in clinical or radiological outcome of root canal therapy with three different types of sealers used in this study.

Conclusions:

MTA could be used as a root canal sealer with equal effectiveness compared with epoxy resin and zinc oxide eugenol sealers. Further long-term studies should be carried out to prove the effectiveness.

Multi-dimensionality of chronic pain of the oral cavity and face

Orofacial pain in its broadest definition can affect up to 7% of the population. Its diagnosis and initial management falls between dentists and doctors and in the secondary care sector among pain physicians, headache neurologists and oral physicians. Chronic facial pain is a long term condition and like all other chronic pain is associated with numerous co-morbidities and treatment outcomes are often related to the presenting co-morbidities such as depression, anxiety, catastrophising and presence of other chronic pain which must be addressed as part of management . The majority of orofacial pain is continuous so a history of episodic pain narrows down the differentials. There are specific oral conditions that rarely present extra orally such as atypical odontalgia and burning mouth syndrome whereas others will present in both areas. Musculoskeletal pain related to the muscles of mastication is very common and may also be associated with disc problems. Trigeminal neuralgia and the rarer glossopharyngeal neuralgia are specific diagnosis with defined care pathways. Other trigeminal neuropathic pain which can be associated with neuropathy is caused most frequently by trauma but secondary causes such as malignancy, infection and auto-immune causes need to be considered. Management is along the lines of other neuropathic pain using accepted pharmacotherapy with psychological support. If no other diagnostic criteria are fulfilled than a diagnosis of chronic or persistent idiopathic facial pain is made and often a combination of antidepressants and cognitive behaviour therapy is effective. Facial pain patients should be managed by a multidisciplinary team.

Patient-centered endodontic outcomes: a narrative review

INTRODUCTION

Root canal treatment (RCT) success criteria inform us of the path to bony healing and of prognostic factors, but tell little about how the patient perceives, feels, or values RCT. Patients choose, undergo, and pay for RCT, they live with the result, and inform their community. The purpose of this narrative review was to appraise patient-centered outcomes of initial non-surgical RCT and nonsurgical retreatment, in adults.

MATERIALS AND METHODS

Patient-centered RCT outcome themes were identified in the extant literature: quality of life, satisfaction, anxiety, fear, pain, tooth survival and cost. Narrative review was applied because the disparate themes and data were unsuited to systematic review or meta-analysis.

RESULTS

Application of the Oral Health Impact Profile (OHIP) demonstrated that disease of pulpal origin affects quality of life with moderate severity, primarily through physical pain and psychological discomfort, and that RCT results in broad improvement of quality of life. Satisfaction with RCT is extremely high, but cost is the primary reason for dissatisfaction. Anxiety and fear affect RCT patients, profoundly influencing their behaviors, including treatment avoidance, and their pain experience. Fear of pain is "fair" to "very much" prior to RCT. Pain is widely feared, disliked, and remembered; however, disease of pulpal origin generally produces moderate, but not severe pain. RCT causes a dramatic decrease in pain prevalence and severity over the week following treatment. Survival rates of teeth after RCT are very high; complication rates are low. Cost is a barrier to RCT, but initial costs, lifetime costs, cost effectiveness, cost utility, and cost benefit all compare extremely well to the alternatives involving replacement using implants or fixed prostheses.

CONCLUSION

Dentists must strive to reduce anxiety, fear, experienced and remembered pain, and to accurately inform and educate their patients with respect to technical, practical and psychosocial aspects of RCT.

Large-scale clinical endodontic research in the National Dental Practice-Based Research Network: study overview and methods

INTRODUCTION

This article reports on the feasibility of conducting a large-scale endodontic prospective cohort study in The National Dental Practice-Based Research Network. This study was designed to measure pain and burden associated with initial orthograde root canal therapy (RCT) and to explore potential prognostic factors for pain outcomes. The main objectives of this first report in a series are to describe the project's feasibility and methods and the demographics of the sample obtained.

METHODS

Sixty-two dentist practitioner-investigators (ie, 46 generalists and 16 endodontists) in 5 geographic areas were certified within the network and trained regarding the standardized study protocol. Enrollment and baseline data collection occurred over 6 months with postobturation follow-up for another 6 months. Patients and dentists completed questionnaires before and immediately after treatment visits. Patients also completed questionnaires at 1 week, 3 months, and 6 months after obturation.

RESULTS

Enrollment exceeded target expectations, with 708 eligible patient-participants. Questionnaire return rates were good, ranging between 90% and 100%. Patient demographics were typical of persons who receive RCT in the United States (ie, mean age = 48 years [standard deviation = 13 years], with most being female [59%], college educated [81%], white non-Hispanic [86%], and having dental insurance [81%]). The tooth types being treated were also typical (ie, 61% molars, 28% premolars, and 11% anteriors, with maxillary teeth being predominant [59%]).

CONCLUSIONS

This study shows the feasibility of conducting large-scale endodontic prospective cohort studies in the network. Patients were rapidly recruited with high levels of compliance in data collection.

Current evidence on atypical odontalgia: diagnosis and clinical management

Patients with atypical odontalgia (AO) complain of medically unexplained toothache. No evidence-based diagnostic criteria or treatment guidelines are yet available. The present paper addresses seven clinical questions about AO based on current knowledge in the literature and discusses diagnostic criteria and guidelines for treatment and management. The questions are (i) What is the prevalence of AO in the community? (ii) What psychological problems are experienced by patients with AO? (iii) Are there any comorbidities of AO? (iv) Is local anesthesia effective for the relief of pain in AO? (v) Are there any characteristic symptoms of AO other than spontaneous pain? (vi) Are antidepressants effective for treatment of AO? (vii) Are anticonvulsants effective for treatment of AO? Our literature search provided answers for these questions; however, there is insufficient evidence-based data to establish guidelines for the diagnosis and treatment of AO. Overall, some diagnostic criteria for neuropathic pain and persistent dentoalveolar pain disorder may be applied to AO patients. The patient's psychogenic background should always be considered in the treatment and/or management of AO. The clinicians may need to treat AO patients using Patient-Oriented Evidence that Matters approach.

Persistent dento-alveolar pain disorder (PDAP): Working towards a better understanding

• New terminology, persistent dento-alveolar pain disorder (PDAP), and diagnostic criteria have been put forward to address the shortcomings of existing nomenclature, which are associated with unclear criteria. • Arriving at an accurate diagnosis of PDAP is based on excluding other possible aetiologies, and may involve different care providers. • Synthesis of published data suggests that PDAP has a frequency of occurrence following root canal therapy of around 1.6%. • The putative risk factors involved in PDAP are largely unknown, but seem to be similar to those being identified with other post-surgical chronic pain disorders. • The underlying mechanisms involved in the development of and/or perpetuating PDAP are unknown and the approach to treatment remains empiric in nature.

Fluid mechanics in dentinal microtubules provides mechanistic insights into the difference between hot and cold dental pain

Dental thermal pain is a significant health problem in daily life and dentistry. There is a long-standing question regarding the phenomenon that cold stimulation evokes sharper and more shooting pain sensations than hot stimulation. This phenomenon, however, outlives the well-known hydrodynamic theory used to explain dental thermal pain mechanism. Here, we present a mathematical model based on the hypothesis that hot or cold stimulation-induced different directions of dentinal fluid flow and the corresponding odontoblast movements in dentinal microtubules contribute to different dental pain responses. We coupled a computational fluid dynamics model, describing the fluid mechanics in dentinal microtubules, with a modified Hodgkin-Huxley model, describing the discharge behavior of intradental neuron. The simulated results agreed well with existing experimental measurements. We thence demonstrated theoretically that intradental mechano-sensitive nociceptors are not “equally sensitive” to inward (into the pulp) and outward (away from the pulp) fluid flows, providing mechanistic insights into the difference between hot and cold dental pain. The model developed here could enable better diagnosis in endodontics which requires an understanding of pulpal histology, neurology and physiology, as well as their dynamic response to the thermal stimulation used in dental practices.

Frequency of nonodontogenic pain after endodontic therapy: a systematic review and meta-analysis

INTRODUCTION

Little is known about ill-defined pain that persists after endodontic procedures, including an estimate of the problem's magnitude. We conducted a systematic review of prospective studies that reported the frequency of nonodontogenic pain in patients who had undergone endodontic procedures.

METHODS

Nonodontogenic pain was defined as dentoalveolar pain present for 6 months or more after endodontic treatment without evidence of dental pathology. Endodontic procedures reviewed were nonsurgical root canal treatment, retreatment, and surgical root canal treatment. Studies were searched in four databases electronically, complemented by hand searching. A summary estimate of nonodontogenic tooth pain frequency was derived using random-effects meta-analysis.

RESULTS

Of 770 articles retrieved and reviewed, 10 met inclusion criteria, and nine had data on both odontogenic and nonodontogenic causes of pain. A total of 3,343 teeth were enrolled within the included studies and 1,125 had follow-up information regarding pain status. We identified 48 teeth with nonodontogenic pain and estimated a 3.4% (95% confidence interval, 1.4%-5.5%) frequency of occurrence. In nine articles containing data regarding both odontogenic and nonodontogenic causes of tooth pain, 56% (44/78) of all cases were thought to have a nonodontogenic cause.

CONCLUSIONS

Nonodontogenic pain is not an uncommon outcome after root canal therapy and may represent half of all cases of persistent tooth pain. These findings have implications for the diagnosis and treatment of painful teeth that were previously root canal treated because therapy directed at the tooth in question would not be expected to resolve nonodontogenic pain.