Tooth survival following root canal treatment by general dental practitioners in a Swedish county - a 10-year follow-up study of a historical cohort

The tooth survival of non-surgical root-filled posterior teeth and the associated prognostic tooth-related factors: A systematic review and meta-analysis

BACKGROUND

Analysis of the survival of root-filled posterior teeth and the associated prognostic tooth-related factors will enable clinicians to predict the outcome of root canal treatment.

OBJECTIVES

To investigate (i) the survival of root-filled posterior teeth and (ii) the tooth-related factors that may affect their survival.

METHODS

Randomized controlled trials, comparative studies and observational studies assessing survival rates of root-filled posterior teeth with a minimum 4-year follow-up period were identified through an electronic search of the following databases up to January 2023: The Cochrane Central Register of Controlled Trials, Medline via PubMed, the Cochrane Database of Systematic Reviews, Embase, Web of Science and NIHR centre for reviews and dissemination. Two reviewers (SP and ML) independently selected the final studies based on pre-defined inclusion criteria. The Newcastle Ottawa Scale and the Cochrane Risk of Bias Tool for Randomized Trials were used to assess the risk of bias. Pooled weighted survival rates were analysed using a random effects meta-analysis model using DerSimonean and Laird methods. Descriptive analysis of studies describing any prognostic tooth-related factors was conducted.

RESULTS

Of the 72 studies identified, data from 20 studies were included in the survival meta-analysis, and data from 13 of these studies were included in the descriptive analysis of tooth-related factors; 12 studies were retrospective, 7 were prospective, and one was a randomized control trial. The pooled survival rates at 4-7 years and 8-20 years of root-filled posterior teeth regardless of tooth type was 91% (95% CI, 0.85; 0.95) and 87% (95% CI, 0.77; 0.93), respectively. The prognostic tooth-related factors mentioned in the included studies were (i) remaining coronal tooth structure, (ii) ferrule, (iii) crown-to-root ratio (iv) tooth type and location (v) periodontal disease (vi) proximal contacts and (vii) cracks.

CONCLUSIONS

The meta-analysis suggests that root canal treatment has a high medium to long term survival outcome. The narrative summary identified 7 factors that affect tooth survival. However, there is a paucity of evidence, and more research is needed in this area.

REGISTRATION

PROSPERO Registration: CRD42021227213.

Further Interventions after Root Canal Treatment Are Most Common in Molars and Teeth Restored with Direct Restorations: A 10-11-Year Follow-Up of the Adult Swedish Population

INTRODUCTION

The aims were to investigate 1) the frequency of nonsurgical retreatment, root-end surgery, extraction, and further restorative treatment during a follow-up of 10-11 years after root filling and compare the frequencies according to tooth group and type of coronal restoration and 2) the timing of nonsurgical retreatment, root-end surgery, and extraction.

METHODS

Data were collected from the Swedish Social Insurance Agency's register. A search for treatment codes identified teeth root filled in 2009 and the type of coronal restoration (direct, indirect, and unspecified) registered within 6 months of root filling. The root-filled teeth were followed 10-11 years, and further interventions were recorded. Descriptive statistics and chi-square tests were used for statistical analysis.

RESULTS

In 2009, root fillings were registered for 215,611 individuals/teeth. Nonsurgical retreatment, root-end surgery, and extraction were undertaken in 3.5%, 1.4%, and 20% teeth, respectively. The frequency of further interventions varied with respect to tooth group and type of coronal restoration, but only slightly for endodontic retreatments. Further interventions, except for root-end surgery, were registered more often for molars and directly restored teeth (P < .001). The majority of endodontic retreatments were undertaken within 4 years, while extractions were evenly distributed over 10-11 years.

CONCLUSIONS

The frequency numbers of nonsurgical retreatment and root-end surgery were low, despite 1 in 5 root-filled teeth registered as extracted. Further interventions were most common in molars and directly restored teeth. Endodontic retreatments were performed more often during the first 4 years.

Survival of endodontically treated teeth in public dental service in Northern Finland: a practise-based register study

OBJECTIVE

The aim of this study was to explore the factors associated with the survival of root canal treated teeth in a practise-based study setting in a 5-year period.

MATERIAL AND METHODS

This retrospective study used data from the electronic patient registration system of the public dental services of the City of Oulu, Finland. The inclusion criteria for this study were patients aged ≥ 20 years who had root canal treatment (RCT) that was initiated in 2014. One RCT per patient was included in the study. A total of 713 patients met the inclusion criteria. The outcome variable for this study was the extraction of the RCT tooth during the 5-year period. Explanatory variables included age, diagnosis, tooth type (incisive, canine, premolar, molar), RCT technique (manual, motorized), time from RCT initiation to final restoration and type of final restoration (composite, glass ionomer, fixed dental prosthesis). To evaluate the association between the outcome variable and explanatory variables, Cox regression analyses were performed.

RESULTS

The overall survival rate was 91%. The middle-aged (40-59-years-old) and the oldest (60 and older) patients had a two-fold risk of extraction compared to younger (20-40-years-old) patients. Similarly, a short length of time from RCT initiation to final restoration (0-14 days) resulted in a nearly three times higher risk of extraction compared to a longer period (≥ 90 days).

CONCLUSIONS

The 5-year survival rate of RCTs seems high. Extractions were more common among patients over 40 years of age and if the RCT was completed shortly after its initiation.

General dental practitioners' fees for root canal treatment, coronal restoration and follow-on treatment in the adult population in Sweden: A 10-year follow-up of data from the Swedish Dental Register

OBJECTIVES

To analyze the accumulated fees connected with root filling, permanent coronal restoration and follow-on treatment charged by Swedish dentists over a 10-11-year follow-up period. Furthermore, analyzing these fees with reference to the type of restoration, tooth group, and the root-filled teeth which survived compared to those requiring extraction.

MATERIAL AND METHODS

In 2009, the data register of the Swedish Social Insurance Agency recorded a total of 215,611 teeth as root-filled. The accumulated fees for each tooth encompassed the following interventions: initial root filling, coronal restorations, and follow-up treatments during the designated period. The outcomes were analyzed using descriptive and analytic statistics, including t tests and one-way analysis of variance. The fees are presented in Euros (€1 = SEK 8.94).

RESULTS

The total accumulated fees for root fillings amounted to 72 million Euros: the mean fee per root filled tooth was €333.6. The total mean fee over a 10-11-year period, comprising root canal treatment, coronal restorations, and any follow-up treatments, was €923.4. Root-filled teeth with indirect restorations presented a higher mean fee (€1 279.3) compared to those with direct restorations (€829.4) or those without specified restorations (€832.7; p < .001). Moreover, molars presented a significantly higher mean fee (€966.4) compared to premolars (€882.8) and anterior teeth (€891.3; p < .001). Lastly, the mean fee for extracted teeth was €1225.3, which was higher compared to those who survived the follow-up period (€848.0; p < .001).

CONCLUSIONS

Fees charged by general dental practitioners for root-filled teeth accumulate over time, probably due to the need for further treatment of the tooth. The total mean fee was significantly higher for molars and root-filled teeth with indirect restorations. However, an analysis of the total costs would require prospective clinical cost-effectiveness studies.

Effectiveness of root canal treatment for vital pulps compared with necrotic pulps in the presence or absence of signs of periradicular pathosis: A systematic review and meta-analysis

BACKGROUND

Preoperative pulpal status may influence the outcomes of root canal treatment (RCTx) according to various measures used.

OBJECTIVES

To compare the effectiveness of RCTx of teeth with a vital pulp versus a necrotic pulp, using a range of clinical and patient-related outcomes proposed for the development of S3-level clinical practice guidelines.

METHODS

A search was conducted in the PubMed-MEDLINE, Scopus, EMBASE, Google scholar databases and available repositories, followed by hand searches, until 29 March 2022. Clinical studies published in the English language comparing the stipulated outcomes of RCTx of teeth with vital versus necrotic pulp were included. The Newcastle-Ottawa Scale was adapted to assess study quality. Effects of pulpal status were estimated and expressed as risk ratio (RR) using fixed- and random-effect meta-analyses. The quality of evidence was assessed through the Grading of Recommendations Assessment, Development and Evaluation tool.

RESULTS

Twenty-eight studies published between 1961 and 2021 were included. Five studies have investigated the "tooth survival" outcome, four reported pulpal status was not a significant predictor, consistent with meta-analysis findings (RR: 1.00; 95% CI: 1.00, 1.00; n = 3). Seven studies reported pulpal status had no significant influence on postoperative pain, regardless of duration after treatment. Sixteen studies have analysed "periapical health," and 11 revealed pulpal status had no significant influence. Meta-analyses revealed the influence was not significant if preoperative periapical radiolucency was absent (RR: 0.95; 95% CI: 0.90, 1.00; n = 9) but significant if it was present (RR: 1.12; 95% CI: 1.05, 1.19; n = 11). Most studies were classified as "some concerns" (n = 17) to "low" (n = 9) risk of bias RoB.

DISCUSSION

Evidence is limited and only available for three outcomes when comparing the effectiveness of RCTx in permanent teeth with vital pulp versus pulp necrosis. Nevertheless, the quality of available evidence was moderate to high. The "periapical health" data heterogeneity could be explained by preoperative radiolucency, thus RCTx was found more effective for prevention than the resolution of apical periodontitis.

CONCLUSIONS

There was no significant difference in the "tooth survival," "postoperative pain" and "evidence of apical radiolucency" outcomes of RCTx in teeth with vital or necrotic pulps.

REGISTRATION

PROSPERO database (CRD42021260280).

Patient-related outcomes and Oral Health-Related Quality of Life in endodontics

There is increased interest in outcome measures that complement the classic goal of endodontics, being the prevention and healing of apical periodontitis. Possible outcome measures can be subdivided into patient-centred outcomes (PCOs), encompassing data collected by nonpatients aiming to assess the effectiveness of an intervention and patient-reported outcomes (PROs), which are reported directly by the patient. PROs can be subsequently classed into PRO measures that ascertain patients' view of their symptoms, their functional status, and their health-related quality of life, and patient-reported experience measures that focus on aspects including the humanity of care, patient satisfaction, patient preference and adherence, personal costs, expectation fulfilment, and decision regrets. The present review aims to define various patient-related outcomes and discuss the literature available regarding PCOs and PROs in endodontics. This includes those proposed to assess the effectiveness of endodontic treatment for pulpitis and apical periodontitis for use in the development of European Society of Endodontology S3-level clinical practice guidelines that have been included by all working groups, except for the radiographic assessment of apical periodontitis. Based on limited evidence in the field, it can be summarized that after recall periods of various lengths, endodontic treatment is associated with a high likelihood of tooth survival and limited need for further intervention, including extraction and further restorative procedures. Oral Health-Related Quality of Life (OHRQoL) is likely to improve following the completion of treatment. Nonetheless, the literature assessing the association between OHRQoL and endodontics is hampered by the use of instruments that have not been previously validated. Amongst the remaining outcome measures discussed in the present review, it is worth highlighting that there is only one study assessing exacerbations in teeth with the presence of endodontic pathosis, which suggests a very low incidence of this adverse effect following endodontic treatment. Patients' expectation fulfilment, adherence, and satisfaction are closely inter-related and depend also on various nonclinical factors. Further studies assessing PCOs and PROs, in association with healing and prevention of apical periodontitis, are required to better understand endodontic treatment from the perspective of patients.

Tooth survival after endodontic treatment

BACKGROUND

There are several measures that are, or could be, in use in relation to estimating the outcome of endodontic treatments. It is important to reflect on when and why a certain outcome measure is used; when caring for an individual patient it is obvious that the goal always should be a tooth in a healthy state, that is striving to remove any infection and aim for the tooth to have healthy periapical tissues. For patients in general and for society, it is also interesting to know if endodontic treatments will lead to retention of teeth in a functioning state. From epidemiological studies, with high prevalence of root filled teeth with periapical radiolucencies, it is implied that dentists and/or patients accept the retention of a root filled tooth with persistent apical periodontitis. In conjunction with an endodontic treatment the prognosis is considered and since the prognostic factors seem to be somewhat different depending on whether one is considering for example the outcome 'healthy periapical tissues' or 'tooth survival' they are equally important to know. Factors affecting the outcome 'healthy periapical tissues' probably has to do with removal of infection and reconstituting the barrier to prevent leakage whilst 'tooth survival' is more likely associated with factors outside of the classical endodontic field such as restorability and avoidance of further destruction of tooth substance. Objective This narrative review will focus on tooth survival after endodontic treatment and root canal treatment will be the focus. Method The search was performed in PubMed. Results As a crude estimation, there is to be an annual loss of 2% of teeth which have received a root canal treatment. Conclusion Of the pre-, peri- and postoperative factors that have been studied in conjunction with root canal treatments the restoration of the tooth is the factor that has been most extensively studied. Many studies imply that root filled teeth restored with indirect restorations have a better survival than teeth restored with direct restorations, it is not possible to determine whether this indeed is a prognostic factor. Registration None.

Additional Treatment Indicative of an Unfavorable Endodontic Outcome in a Swedish County-A 10-year Observational Study

INTRODUCTION

This study's aim was to calculate the incidence of first additional endodontic treatment or extraction as the result of an unfavorable endodontic outcome following orthograde root canal treatment (RCT) performed by general dental practitioners during a 10-year period and to identify possible predictors for outcomes.

METHODS

A randomized cohort of 280 individuals (and as many teeth) with an orthograde RCT was followed for over 10 years. Dental records were reviewed, and individuals were recalled when data were missing. The following terminal events indicative of unfavorable endodontic treatment outcome were orthograde retreatment, surgical endodontics, and tooth extractions exclusively due to endodontic reasons. Selected variables related to individuals and treatment (pre-, intra-, and postoperative) were harvested to analyze possible associations with the terminal events. Unadjusted survival analysis and Cox regression analysis were performed and P < .05 was considered statistically significant.

RESULTS

Terminal events were registered for 22 teeth/individuals and 17 of these were orthograde retreatments. The cumulative 10-year survival of RCTs was 92.7% (standard error 1.7%), with a higher yearly incidence during the first 2 years. The univariate analysis identified 5 factors associated with the outcome. There were too few events to perform a multivariate analysis.

CONCLUSIONS

The mean incidence of additional treatment indicative of unfavorable endodontic outcome was 0.7% per year during the first 10 years, but the mean incidence was greater during the first 2 years. Five factors were associated with an unfavorable outcome; however, confounders cannot be excluded from the associations.

Root Canal Treatment Survival Analysis in National Dental PBRN Practices

Few studies have examined the longevity of endodontically treated teeth in nonacademic clinical settings where most of the population receives its care. This study aimed to quantify the longevity of teeth treated endodontically in general dentistry practices and test the hypothesis that longevity significantly differed by the patient's age, gender, dental insurance, geographic region, and placement of a crown and/or other restoration soon after root canal treatment (RCT). This retrospective study used deidentified data of patients who underwent RCT of permanent teeth through October 2015 in 99 general dentistry practices in the National Dental Practice-Based Research Network (Network). The data set included 46,702 patients and 71,283 RCT permanent teeth. The Kaplan-Meier (product limit) estimator was performed to estimate survival rate after the first RCT performed on a specific tooth. The Cox proportional hazards model was done to account for patient- and tooth-specific covariates. The overall median survival time was 11.1 y; 26% of RCT teeth survived beyond 20 y. Tooth type, presence of dental insurance any time during dental care, placement of crown and/or receiving a filling soon after RCT, and Network region were significant predictors of survival time (P < 0.0001). Gender and age were not statistically significant predictors in univariable analysis, but in multivariable analyses, gender was significant after accounting for other variables. This study of Network practices geographically distributed across the United States observed shorter longevity of endodontically treated permanent teeth than in previous community-based studies. Also, having a crown placed following an RCT was associated with 5.3 y longer median survival time. Teeth that received a filling soon after the RCT before the crown was placed had a median survival time of 20.1 y compared to RCT teeth with only a crown (11.4 y), only a filling (11.2 y), or no filling and no crown (6.5 y).

Treatment Outcome and Root Canal Preparation Techniques: 5-Year Follow-Up

OBJECTIVE

This study aims at comparing treatment outcome and tooth survival of root canal-filled teeth following manual vs rotary instrumentation techniques over a 5-year period.

METHODS

This was a single-centre study conducted as a follow-up to a short-term parallel-arm randomised controlled noninferiority trial in which root canal treatment was performed on teeth using either rotary or manual instrumentation. Patients were monitored at post 6-month, 1-year, 4-year, and 5-year review periods by blinded evaluators. Treatment outcome was categorised as favourable, uncertain, and unfavourable (employing European Society of Endodontology categorisation based on strict clinical and radiographic criteria), and 5-year tooth survival was determined by assessing whether tooth was in situ in the oral cavity or extracted. The Kaplan-Meier method and log rank test evaluated tooth survival. P value <.05 was considered statistically significant.

RESULTS

Ninety of 120 treated teeth were assessed in 37 men and 40 women with mean age of 30.6 ± 10.99 years. Treatment outcome was significantly more favourable in the rotary group compared to the manual group at post 6-month (P = .021) and 1-year (P = .043) review periods. The differences in favourable outcome (P = .498) and tooth survival (P = .296) between the 2 groups were, however, not significant at the 5-year review period.

CONCLUSIONS

The rotary instrumentation technique was shown to be more effective in resolving clinical symptoms and promoting periapical healing after the post 6-month and 1-year review compared to the manual instrumentation technique; however, both groups had similar favourable outcomes and survival rates after an extended 5-year review period.

Patient record assessment of results and related resources spent during one year after initiation of root canal treatment in a Swedish public dental organisation

Aim

To document treatment outcomes and related resources, in patients undergoing root canal treatment (RCT) in county public dental clinics, by monitoring patient records for 12 months from treatment start.

Methodology

The subjects comprised 243 patients starting RCT at 20 public dental clinics in Västra Götaland county, Sweden. Their computerized dental records were monitored prospectively for a year after starting their endodontic treatment. Treatment was completed with either a root filling or extraction. The following treatment‐specific variables were registered: number of appointments and days until treatment was completed, possible complications and prescriptions for antibiotics, and for the root filled teeth: type of coronal restoration and further procedures undertaken within the year. The treatment outcomes were compared with the preoperative variables and in a logistic regression analysis.

Results

Complete data were available for 240 patients (98.8%): 128 women and 112 men, with a mean age of 48.5 years (SD = 16.3). Molar teeth predominated (n = 113, 47.1%). Most cases were completed with a root filling (n = 169, 70.4%). The remainder were extracted (n = 32, 13.3%) or were still uncompleted (n = 39, 16.3%). On average, a root filling was completed in 2.4 (SD = 0.9) appointments, or extraction at the third appointment (SD = 1.6). The molars were less often completed and often predominant among the extracted teeth. The indication for extraction was often for endodontic or RCT‐related reasons. Most complications were registered in the molars and antibiotics were prescribed in 20 cases. Most root filled teeth were restored with a direct restoration. Four root filled teeth (2.4%) were extracted within the time period.

Conclusions

Patient records, followed from the start of treatment, show that 12 months on, the root filling had not been completed in just under 30% of the teeth. Of these, about half were extracted. Of particular concern is the outcome for endodontic treatment of molar teeth. In the general practice setting, molar endodontics are not only technically challenging but also very demanding in terms of chairside resources. In the present study, a successful outcome was achieved in just over half the cases.