Outcomes of Primary Root Canal Therapy: An updated Systematic Review of Longitudinal Clinical Studies Published between 2003 and 2020

Background

A comprehensive effort to evaluate outcomes of primary root canal therapy (RCT) between 1966 and 2002 was published by Ng et al. (2007, International Endodontic Journal, 40, 921; 2008, International Endodontic Journal, 41, 6). Changes in endodontic materials and treatment methods warrant an updated analysis of outcomes.

Objectives

This study aimed to (1) quantify the success rates of primary RCT published between 2003 and 2020; and (2) investigate the influence of some characteristics known/suspected to be associated with treatment outcomes.

Methods

An electronic search was performed in the following databases (01‐01‐2003 to 12‐31‐2020): Pubmed, Embase, CINHAL, Cochrane and Web of Science. Included study designs were longitudinal clinical studies (randomized control trials, cohort studies, retrospective observational studies). Studies with at least twelve‐months of post‐operative review and success rates based on clinical and radiographic criteria were analysed. The terms ‘strict’ (complete resolution of periapical lesion) or ‘loose’ (reduction in size of existing periapical lesion) were used to describe the outcome criteria. Weighted, pooled success rates were calculated. Random effects meta‐regression models were used to investigate potential sources of statistical heterogeneity. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to evaluate for quality assessment of the included studies.

Results

Forty‐two studies were included in the review. Meta‐analyses showed that the weighted pooled success rates were estimated to be 92.6% (95% CI: 90.5%–94.8%) under ‘loose criteria’ and 82.0% (95% CI: 79.3%–84.8%) under ‘strict’ criteria. The most significant areas of study heterogeneity were year of publication and qualification of operator. The majority (64.29%) of studies were considered to be of low quality of evidence.

Discussion

Biological factors continue to have the most significant impact on RCT outcomes. The technological method of instrumentation had no significant effect. The quality of evidence was based primarily on study design and only randomized control trials were considered to be ‘high’ quality of evidence.

Conclusions

The reported success rates show improvement over time. Weighted success rates for studies with a minimum of four‐years follow‐up had better outcomes, compared to those with less than four years, when ‘strict criteria’ were used.

Registration

PROSPERO database (CRD42021226311).

Clinical cell-based versus cell-free regenerative endodontics: clarification of concept and term

There is no consensus on the true meaning of clinical regenerative endodontics, and there is confusion over the concept and the term. Commonly used terms include revitalization and revascularization. The clinical methods for endodontic revitalization procedures and the tissue engineering concept differ depending on whether there is exogenous delivery of cells - called cell therapy, or not. Here, in this review, the difference is clarified by emphasizing the correct terminology: cell-free versus cell-based regenerative endodontic therapy (CF-RET versus CB-RET). The revitalization procedures practised clinically do not fit into the modern tissue engineering concepts of pulp regeneration but can be categorized as CF-RET. The modern tissue engineering concept in pulp regeneration is a CB-RET, which so far is at the clinical trial stage. However, histological examination of teeth following regenerative endodontic treatments reveals healing with repair derived from stem cells that originate from the periodontal, bone and other tissues. The aim of regenerative endodontics is regeneration of the pulp-dentine complex. This review discusses why CF-RET is unlikely to regenerate a pulp-dentine complex with current protocols. The American Association of Endodontists and the European Society of Endodontology have not yet recommended autologous stem cell transplantation (CB-RERT) which aspires for regeneration. Therefore, an understanding of the concept, term, difficulties and differences in current protocols is important for the clinician. However, rather than being discouraged that ideal regeneration has not been achieved to date, repair can be an acceptable outcome in clinical regenerative endodontics as it has also been accepted in medicine. Repair should also be considered in the context that resolution of the clinical signs/symptoms of pulp necrosis/apical periodontitis is generally reliably obtained in clinical regenerative endodontics.

Regenerative endodontics: a comprehensive review

The European Society of Endodontology and the American Association for Endodontists have released position statements and clinical considerations for regenerative endodontics. There is increasing literature on this field since the initial reports of Iwaya et al. (Dental Traumatology, 17, 2001, 185) and Banchs & Trope (Journal of Endodontics, 30, 2004, 196). Endogenous stem cells from an induced periapical bleeding and scaffolds using blood clot, platelet rich plasma or platelet-rich fibrin have been utilized in regenerative endodontics. This approach has been described as a 'paradigm shift' and considered the first treatment option for immature teeth with pulp necrosis. There are three treatment outcomes of regenerative endodontics; (i) resolution of clinical signs and symptoms; (ii) further root maturation; and (iii) return of neurogenesis. It is known that results are variable for these objectives, and true regeneration of the pulp/dentine complex is not achieved. Repair derived primarily from the periodontal and osseous tissues has been shown histologically. It is hoped that with the concept of tissue engineering, namely stem cells, scaffolds and signalling molecules, that true pulp regeneration is an achievable goal. This review discusses current knowledge as well as future directions for regenerative endodontics. Patient-centred outcomes such as tooth discolouration and possibly more appointments with the potential for adverse effects needs to be discussed with patients and parents. Based on the classification of Cvek (Endodontics and Dental Traumatology, 8, 1992, 45), it is proposed that regenerative endodontics should be considered for teeth with incomplete root formation although teeth with near or complete root formation may be more suited for conventional endodontic therapy or MTA barrier techniques. However, much is still not known about clinical and biological aspects of regenerative endodontics.

[International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 3. Injuries in the primary dentition. Hebrew edition]

Traumatic injuries to the primary dentition present special problems and the management is often different as compared with the permanent dentition. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialities were included in the task group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care for management of primary teeth injuries. The IADT cannot and does not guarantee favorable outcomes from strict adherence to the guidelines, but believe that their application can maximize the chances of a positive outcome. The Hebrew Edition is part of the IADT global effort to provide a worldwide accessibility to these guidelines. This third part will discuss injuries in the primary dentition.

[International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Hebrew edition]

Avulsion of permanent teeth is one of the most serious dental injuries, and a prompt and correct emergency management is very important for the prognosis. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the task group. The guidelines represent the current best evidence and practice based on literature research and professionals' opinion. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of avulsed permanent teeth. The Hebrew Edition is part of the IADT global effort to provide a worldwide accessibility to these guidelines. This scond part of the guidelines will focus on avulsion of permanent teeth.

[International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 1. Fractures and luxations of permanent teeth. Hebrew edition]

Traumatic dental injuries (TDIs) of permanent teeth occur frequently in children and young adults. Crown fractures and luxations are the most commonly occurring of all dental injuries. Proper diagnosis, treatment planning and follow up are important for improving a favorable outcome. Guidelines should assist dentists and patients in decision making and for providing the best care effectively and efficiently. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the best current evidence based on literature search and professional opinion. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of TDIs. In this first article, the IADT Guidelines for management of fractures and luxations of permanent teeth will be presented. The Hebrew Edition is part of the IADT global effort to provide accessibility to these guidelines worldwide.

Band erosion after laparoscopic gastric banding: a retrospective analysis of 865 patients over 5 years

BACKGROUND

Gastric band erosion is a well-reported complication after laparoscopic adjustable gastric banding (LAGB). The published literature is limited and inconclusive with regard to its management. The authors therefore reviewed all band erosions detected during a 5-year period in a high-volume bariatric practice. Because a significant proportion of the band insertions (65%) were undertaken by an operator beyond his learning curve, the authors hoped to gain a mature, comprehensive understanding of this significant complication.

METHODS

The authors retrospectively reviewed the operative log of the operating theaters in their obesity surgery unit to find all the operations performed on LAGB patients for erosion from January 2003 to December 2007. The clinical notes and electronic records for each patient were reviewed. These data were cross-referenced against the authors' obesity surgery database, and denominator data such as the total number operations performed and demographics were found. Finally, postoperative outcomes were collated from the outpatient follow-up data and telephonic interviews, and the results were analyzed.

RESULTS

From January 2003 to December 2007, a single surgeon performed 865 LAGBs in the authors' unit. The authors identified 18 operations performed for LAGB erosions. The 18 patients (one referred from elsewhere, 14 women) formed the final study cohort (median preoperative body mass index [BMI], 46 kg/m(2)). Of the 17 erosions, 15 occurred relatively early in the series. The patients with the 213 Swedish adjustable gastric bands experienced 12 erosions (incidence, 5.6%) compared with 6 erosions with the 652 LAP-BANDs (incidence, 0.9%). The median time to presentation was 7 months (range, 1-60 months). However, 55% of the erosions (n = 10) occurred within the first year, and only 10% occurred after the second year. The most common presenting symptom was pain followed by weight regain. None of the patients experienced peritonitis. After surgical management of the erosion, three patients had a second LAGB and at this writing are well. Of the remaining patients, 11 are well, but 6 of these patients have returned to their previous weight (4 patients were lost to follow-up evaluation).

CONCLUSIONS

The overall incidence of LAGB erosions in our series was 1.96%. This incidence fell with increasing experience to 0.5% after the initial 300 bands were excluded from the analysis (3 band erosions in the last 565 band insertions). However, further increases in incidence are likely with a longer follow-up period. The most common presentation was abdominal pain followed by weight regain and port-site sepsis. In the authors' hands, laparoscopic omental plugging and band removal through a separate anterior gastrotomy appear to be effective methods for dealing with band erosions. Band erosion is a significant source of morbidity, with at least one-third of the erosion patients in our series not achieving their final goal of weight loss despite appropriate treatment. This study highlights the need for a future prospective randomized study to clarify the apparent strong influence of band design and construction on the etiopathogenesis of band erosion.

Variation of outcome in weight loss with band volume adjustments under clinical and radiological control following laparoscopic adjustable gastric banding

BACKGROUND

Following laparoscopic adjustable gastric banding (LAGB), patients usually undergo follow-up (FU) to optimize weight loss and detect complications, with band-volume adjustment performed either under radiological or clinical guidance with no current consensus on what is the best standard of care. We, therefore, analyzed our patient cohort to identify differences between the two, if any, over a 3-year period.

METHODS

We retrospectively reviewed our obesity surgery database to find all LAGB patients and grouped them based on method of FU without weight exclusions. We then selected out 70 consecutive patients from each cohort from an arbitrary time-point to achieve sufficient FU and analyzed the results from the data collated. Patients with postoperative complications were excluded to prevent bias.

RESULTS

From 2003 to 2007, there were 865 LAGB performed in our unit. We identified 70 consecutive patients from January 2004 from each cohort. After review and exclusions, we were left with 50 patients in the radiology group (RG) and 49 in the clinical group (CG) [median BMI 43.8 and 47.1, respectively; median age 43 years in both]. Routine FU was at weekly, then fortnightly, and monthly intervals, but results were analyzed at 3-month intervals until the first year and every 12 months until the third year. The median percentage of excessive weight loss was 22% and 36% at 6 months; 28% and 43% at 12 months; 27% and 47% at 2 years; and 33% and 46% at 3 years in the RG and CG, respectively. There was no difference in difficulties to band fill in either group as per clinical records, although there was a greater incidence of port damage in the CG.

CONCLUSIONS

Our study suggests that at medium-term follow-up, clinical fill is superior to radiological FU at least in terms of weight loss, with the added benefit of avoiding unnecessary radiation albeit that the difference between the two methods gets smaller with FU beyond 2 years. This topic merits a future randomized control trial to make recommendations without biases inherent to retrospective analysis.

Influence of psychological factors on risk of temporomandibular disorders

Psychological characteristics potentially may be a cause or consequence of temporomandibular disorder (TMD). We hypothesized that psychological characteristics associated with pain sensitivity would influence risk of first-onset TMD, but the effect could be attributed to variation in the gene encoding catechol-O-methyltransferase (COMT). We undertook a prospective cohort study of healthy female volunteers aged 18-34 yrs. At baseline, participants were genotyped, they completed psychological questionnaires, and underwent quantitative sensory testing to determine pain sensitivity. We followed 171 participants for up to three years, and 8.8% of them were diagnosed with first-onset TMD. Depression, perceived stress, and mood were associated with pain sensitivity and were predictive of 2- to 3-fold increases in risk of TMD (P < 0.05). However, the magnitude of increased TMD risk due to psychological factors remained unchanged after adjustment for the COMT haplotype. Psychological factors linked to pain sensitivity influenced TMD risk independently of the effects of the COMT haplotype on TMD risk.

Gastric bezoar complicating laparoscopic adjustable gastric banding with band slippage

Gastric bezoars may develop in the proximal pouch after gastric restriction, eg. by laparoscopic adjustable gastric banding (LAGB). To date, only two centers have reported this rare complication. We report an additional case with band slippage, to emphasize that bezoars should be considered in the differential diagnosis in patients presenting with new onset nausea and vomiting after LAGB.

Laparoscopic repair of large paraesophageal hiatus hernia: quality of life and durability

BACKGROUND

Laparoscopic repair of large paraesophageal hiatus hernias (LPOHH) is shown to be a safe and effective operation in the short term. However, its long-term durability and its effect on quality of life are less well established. This study aimed to assess the midterm outcome for laparoscopic repair of LPOHH with validated quality-of-life symptom scores and barium studies.

METHODS

Between January 2000 and July 2004, 49 patients (27 women) with LPOHH underwent laparoscopic repair. The median age of these patients was 68 years (range, 38-90 years). The laparoscopic repair included resection of the hernia sac, reduction of its contents, esophageal mobilization up to the aortic arch, crural repair with sutures (mesh reinforcement in 17 cases), Nissen fundoplication, and fixation of the wrap to the crura. Follow-up assessment was prospective with quality-of-life questionnaires, the Gastrointestinal Symptom Rating Scale (GSRS), the Gastroesophageal Reflux Disease-Health-Related Quality of Life (GERD-HRQOL) scale, and barium studies.

RESULTS

The presenting symptoms were pain for 21 patients, reflux for 27 patients, bleeding or anemia for 14 patients, and dysphagia for 17 patients. Five emergency operations were performed. Short esophagus was present in 24 patients. There were two conversions to open surgery. The major morbidity (atrial fibrillation, pulmonary embolism, and splenectomy) rate was 10.2%, and the minor morbidity (chest infection, jaundice, dysphagia, small pneumothorax) rate was 20.4%. Six patients were deceased of unrelated causes at the time of follow-up evaluation. Responses to the questionnaires were obtained in 31 cases (75%). Using the Wilcoxon signed rank test, the results from the questionnaires showed a statistically significant improvement (p < 0.001) in abdominal pain, reflux, and indigestion scores (GSRS) and GERD-HRQOL scores. Follow-up barium studies for 27 patients (66%) showed recurrence in 4 patients (14.8%), 2 of which were symptomatic.

CONCLUSION

Laparoscopic repair of LPOHH is associated with good quality of life as well as an acceptable midterm recurrence rate.

Healing of apical periodontitis after endodontic treatment: a comparison between a silicone-based and a zinc oxide-eugenol-based sealer

AIM

To assess the treatment results up to 1 year after endodontic treatment of apical periodontitis using a silicone-based sealer in comparison with Grossman's sealer, and to compare the results at 3 months after treatment with the 12-month follow-up to assess the prognostic value of a 3-month control.

METHODOLOGY

A total of 199 teeth were treated at three centres. The sealer was randomly chosen at the time of filling. Treatment results were evaluated clinically and radiographically 3 and 12 months after root-canal filling. The periapical status was evaluated using the periapical index (PAI).

RESULTS AND CONCLUSIONS

Average PAI scores decreased from 3.43 at start to 2.21 at 12 months for Grossman's sealer and from 3.40 to 2.26 for the silicon-based material. No significant difference between the groups at start or any of the follow ups was seen. The 3-month control was adequate in establishing significant healing in both groups. The improvement of the periapical condition continued at the 12-month examination.

The long term results of endoscopic surveillance of premalignant gastric lesions

BACKGROUND

A large proportion of patients attending open access endoscopy have histological and gross pathological findings that are potentially premalignant. The proportion of these patients who go on to develop malignancies and the timescale over which this occurs are uncertain.

AIMS

This study aims to discover the incidence of gastric cancers in this "high risk" group and to examine the potential for their early diagnosis and treatment.

PATIENTS

A total of 1753 patients attended open access endoscopy. From these, 166 patients with dysplasia, intestinal metaplasia, atrophic gastritis, foveolar hyperplasia, regenerative changes, polyps, or ulcers who agreed to undergo annual surveillance endoscopy were studied.

METHODS

Patients were endoscoped annually. Additionally, patients with ulcers were re-examined at two monthly intervals until ulcer healing. Cancers detected were treated by gastrectomy.

RESULTS

Twenty two of 1753 patients attending open access endoscopy had gastric cancer (1.3%). In the study population, 14 cancers were detected over 10 years (8.4 %). These were of an earlier stage than those detected at open access (stage I and II 67% v 23%; p<0.05) and five year survival was significantly higher (50% v 10%; p=0.006). In atrophic gastritis and intestinal metaplasia the risk of malignancy was 11%.

CONCLUSIONS

In patients with atrophic gastritis or intestinal metaplasia, annual surveillance can detect most new tumours at an early stage with a major improvement in survival. Potential benefits of such a surveillance programme are large and warrant further investigation in a multicentre randomised controlled trial.

Laser Doppler flowmetry for monitoring traumatized teeth

Laser Doppler Flowmetry (LDF) has been shown to be valuable in monitoring revascularization of immature incisors following severe dental trauma. Several investigators have demonstrated the ability of LDF to record blood flow signals from vital tooth pulps. In this case report, LDF was used for a 7-year-old child patient following a severe luxation of tooth #9. During follow-up examinations the traumatized tooth was unresponsive to traditional vitality testing during the first 6 months; however, LDF indicated that revascularization had occurred much sooner. Until recently, CO2 ice has been the most effective method for sensitivity testing in trauma cases such as presented here. In this case, LDF gave us the assurance that we could defer invasive care during a critical time period when root canal therapy might have been initiated for this child patient.

Bacteria isolated after unsuccessful endodontic treatment in a North American population

OBJECTIVE

The purpose of this study was to determine the composition of the microbial flora present in teeth after the failure of root canal therapy in a North American population. These results were then compared with those of the previous Scandinavian studies.

STUDY DESIGN

Fifty-four root-filled teeth with persistent periapical radiolucencies were selected for retreatment. After removal of the root-filling material, the canals were sampled with paper points, and by reaming of the apical dentin. Both samples were grown under aerobic and strict anaerobic conditions. Then the bacterial growth was analyzed.

RESULTS

The microbial flora was mainly of 1 to 2 strains of predominantly gram-positive organisms. Enterococcus faecalis was the most commonly recovered bacterial species.

CONCLUSIONS

Bacteria were cultivated in 34 of the 54 teeth examined in the study. E faecalis was identified in 30% of the teeth with a positive culture.

Efficacy of laser Doppler flowmetry for the diagnosis of revascularization of reimplanted immature dog teeth

This study was performed to assess if laser Doppler flowmetry (LDF) is an improved method for the detection of revascularization of replanted teeth. Teeth were extracted and reimplanted under different experimental conditions. LDF readings were taken before extraction and weekly for 3 months. In control teeth, LDF baseline readings were taken and then repeated after the apical blood vessels were cut surgically. At the end of 3 months it was determined radiographically and histologically whether revascularization had occurred, i.e. vitality had returned.

RESULTS

LDF readings correctly predicted the pulp status (vital vs. non-vital) in 83.7% of the readings. 73.9% (17 of 23) were correct for the vital teeth and 95% (19 of 20) were correct for the non-vital teeth. Fisher's exact test (2-tail) indicated that there was no significant association between the efficacy of LDF and tooth type (P = 0.166), although P2 was the least accurate tooth tested. Wilcoxon's matched-pair signed rank test demonstrated that in the revascularized (vital) teeth, the flux value between the baseline and week 2 dropped significantly (P = 0.0001), increased significantly from week 2 to week 4 (P = 0.0001) and then decreased steadily until week 12. However, at week 12 the flux was still significantly higher than at week 2 (P = 0.010). In the teeth that failed to revascularize, the flux value dropped significantly by weeks 1 and 2 (P = 0.004 and P = 0.0001, respectively). Flux values did not increase from week 2. A Fast Fourier Transform (FFT) analysis confirmed a pulse of dominant frequency of 2 Hz in the teeth that returned to vitality and the lack thereof in those that stayed non-vital. One tooth in which the flux value evaluation indicated a non-vital tooth but the radiographic/histologic findings showed vital (false negative) possessed a pulse of dominant frequency and proved by this method to have successfully revascularized.