A protocol for the Development of Core Outcome Sets for Endodontic Treatment modalities (COSET): an international consensus process

Background

The outcome of endodontic treatment is generally assessed using a range of patient and clinician-centred, non-standardised clinical and radiographic outcome measures. This makes it difficult to synthesise evidence for systematic analysis of the literature and the development of clinical guidelines. Core outcome sets (COS) represent a standardised list of outcomes that should be measured and reported in all clinical studies in a particular field. Recently, clinical researchers and guideline developers have focussed on the need for the integration of a patient-reported COS with clinician-centred measures. This study aims to develop a COS that includes both patient-reported outcomes and clinician-centred measures for various endodontic treatment modalities to be used in clinical research and practice.

Methods

To identify reported outcomes (including when and how they are measured), systematic reviews and their included clinical studies, which focus on the outcome of endodontic treatment and were published between 1990 and 2020 will be screened. The COSs will be defined by a consensus process involving key stakeholders using semi-structured interviews and an online Delphi methodology followed by an interactive virtual consensus meeting. A heterogeneous group of key ‘stakeholders’ including patients, general dental practitioners, endodontists, endodontic teachers, clinical researchers, students and policy-makers will be invited to participate. Patients will establish, via interactive interviews, which outcomes they value and feel should be included in a COS. In the Delphi process, other stakeholders will be asked to prioritise outcomes identified from the literature and patient interviews and will have the opportunity at the end of the first round to add outcomes that are not included, but which they consider relevant. Feedback will be provided in the second round, when participants will be asked to prioritise the list again. If consensus is reached, the remaining outcomes will be discussed at an online meeting and agreement established via defined consensus rules of outcome inclusion. If consensus is not reached after the second round, a third round will be conducted with feedback, followed by the online meeting. Following the identification of a COS, we will proceed to identify how and when these outcomes are measured.

Discussion

Using a rigorous methodology, the proposed consensus process aims to develop a COS for endodontic treatment that will be relevant to stakeholders. The results of the study will be shared with participants and COS users. To increase COS uptake, it will also be actively shared with clinical guideline developers, research funders and the editors of general dental and endodontology journals.

Trial registration

COMET 1879. 21 May 2021.

Impact of cone beam computed tomography on periapical assessment and treatment planning five to eleven years after surgical endodontic retreatment

AIM

To evaluate how additional information from Cone Beam CT (CBCT) impacts on periapical assessment and treatment planning based on clinical examination and periapical radiographs (PR) in cases followed up five to eleven years after surgical endodontic retreatment (SER).

METHODOLOGY

Patients receiving SER during 2004-2010 were reinvited for follow-up examination including clinical examination, PR, and CBCT. In total, 108 patients (119 teeth) were reinvited, 74 patients (83 teeth) accepted to participate. Three observers initially assessed PR according to the four-scaled, increasing disease severity criteria by Rud et al. (International Journal of Oral Surgery, 1, 1972 and 195) and Molven et al. (International Journal of Oral and Maxillofacial Surgery, 16, and 432): 'Radiographic assessment A'. By including clinical information 'Treatment plan A' was made as follows: 1) no treatment, 2) further observation, 3) SER reoperation (SER-R), or 4) extraction. Hereafter, the CBCT volume was assessed and the information incorporated for 'Radiographic assessment B' followed by 'Treatment plan B'. Agreement between radiographic assessments and between treatment plans was recorded and assessed statistically by Stuart-Maxwell test for marginal homogeneity.

RESULTS

Nine teeth had been extracted; thus, the final analysis included 74 teeth (66 patients). The radiographic assessment was changed as a result of the CBCT evaluation in 38 cases (51.4%), of which 35 (47.3%) were to a higher Rud & Molven score, P < 0.001. The treatment plan was changed for 18 teeth (24.3%). For 14 teeth (18.9%), the change was from no treatment or further observation to a more invasive treatment plan (SER-R or extraction), P = 0.005.

CONCLUSION

The use of CBCT for long-term follow-up after SER led to more cases diagnosed with persisting or recurrent apical periodontitis and hence often to the recommendation of a more invasive treatment modality.

Quality of root fillings performed with two root filling techniques. An in vitro study using micro-CT

Objective.

The aim of this study was to compare the presence of voids in root fillings performed in oval and ribbon-shaped canals with two root filling techniques, lateral compaction technique (LCT) or hybrid technique (HT), a combination of a gutta-percha masterpoint and thermoplastic gutta-percha. Furthermore, the obturation time for the two techniques was evaluated.

Materials and methods.

Sixty-seven roots with oval and ribbon-shaped canals were prepared using Profile Ni-Ti rotary files. After preparation, the roots were randomly allocated to two groups according to root filling technique. All roots were filled with AH plus and gutta-percha. Group 1 was filled using LCT (n = 34) and group 2 was filled using HT (n = 33). The obturation time was measured in 30 cases evenly distributed between the two techniques. Voids in relation to the root canal fillings were assessed using cross-section images from Micro-computed Tomography scans.

Results.

All root canal fillings had voids. Permutation test showed no statistically significant difference between the two root filling techniques in relation to presence of voids (p = 0.092). A statistically significant difference in obturation time between the two techniques was found (p < 0.001).

Conclusion.

The present study found no statistically significant difference in percentage of voids between two root filling techniques. A 40% reduction in obturation time was found for the HT compared to the LCT.

Incidence of caries lesions in approximal surfaces: a radiographic study of a general adult Danish population

The aim was to describe the incidence of caries lesions in a randomly selected adult population, and to identify risk factors related to the incidence of caries lesions in approximal surfaces. In 1997, 616 adults participated in a study including a radiographic survey. In 2003 these individuals were contacted again and offered a second radiographic survey; 473 consented and attended this examination. In approximal surfaces, presence/absence of caries lesions and presence and type of coronal fillings were recorded. The incidence of caries lesions in surfaces with no caries lesions in 1997 was studied. Potential risk factors included information at three levels: (1) person, (2) tooth, and (3) surface. The analysis was carried out by multilevel logistic regression. For the analyses 23,701 approximal surfaces were eligible. In 23,243 approximal surfaces no caries lesions were detected in 1997, 17,007 of these were surfaces without fillings, and 6,236 were filled surfaces. In unfilled surfaces several factors affected the risk for development of a caries lesion: young age, high number of fillings, number of teeth and status of the adjacent surface. In filled surfaces few factors affected the incidence of caries lesions: status of the adjacent surface, smoking and distal surfaces. Differences in risk factor patterns for the incidence of caries lesions were found for unfilled and filled surfaces. The study emphasizes the importance of assessing factors related to the incidence of caries lesions in adults. Further it underlines the need to analyse the fate of filled surfaces separately, because once a surface has received a filling it needs continuous attendance.

Effect of monitor display on detection of approximal caries lesions in digital radiographs

OBJECTIVES

The aim was to compare the accuracy of five flat panel monitors for detection of approximal caries lesions.

METHODS

Five flat panel monitors, Mermaid Ventura (15 inch, colour flat panel, 1024 x 768, 32 bit, analogue), Olórin VistaLine (19 inch, colour, 1280 x 1024, 32 bit, digital), Samsung SyncMaster 203B (20 inch, colour, 1024 x 768, 32 bit, analogue), Totoku ME251i (21 inch, greyscale, 1400 x 1024, 32 bit, digital) and Eizo FlexScan MX190 (19 inch, colour, 1280 x 1024, 32 bit, digital), were assessed. 160 approximal surfaces of human teeth were examined with a storage phosphor plate system (Digora FMX, Soredex) and assessed by seven observers for the presence of caries lesions. Microscopy of the teeth served as validation for the presence/absence of a lesion.

RESULTS

The sensitivities varied between observers (range 7-25%) but the variation between the monitors was not large. The Samsung monitor obtained a significantly higher sensitivity than the Mermaid and Olórin monitors (P<0.02) and a lower specificity than the Eizo and Totoku monitors (P<0.05). There were no significant differences between any other monitors. The percentage of correct scores was highest for the Eizo monitor and significantly higher than for the Mermaid and Olórin monitors (P<0.03).

CONCLUSIONS

There was no clear relationship between the diagnostic accuracy and the resolution or price of the monitor. The Eizo monitor was associated with the overall highest percentage of correct scores. The standard analogue flat panel monitor, Samsung, had higher sensitivity and lower specificity than some of the other monitors, but did not differ in overall accuracy for detection of carious lesions.

Periapical radiography and cone beam computed tomography for assessment of the periapical bone defect 1 week and 12 months after root-end resection

OBJECTIVES

Our aim was to compare periapical radiography and cone beam CT (CBCT) for assessment of the periapical bone defect 1 week and 12 months after root-end resection.

METHODS

50 patients (58 teeth) with a persisting apical periodontitis in a root-filled tooth (incisor, canine or premolar) were treated with root-end resection. 1 week and 12 months post-operatively, a CBCT scan (NewTom 3G) and a periapical radiograph (Digora) were obtained. Three observers detected and measured the periapical bone defects on periapical radiographs and CBCT images (coronal and sagittal sections).

RESULTS

1 week post-operatively, a periapical bone defect area was measured in all teeth by all observers. The defect was 10% smaller on periapical radiographs (mean = 12.4 mm2, SD = 8.2) than on the CBCT images measured in the coronal plane (mean = 13.0 mm2, SD = 7.8), a difference which was not statistically significant (P = 0.58). 12 months post-operatively (n = 52), there was considerable variation between the observers' detection of a remaining defect on the periapical radiographs and the CBCT images. The average agreement between the periapical radiograph and the CBCT images in the coronal sections was 67%, and more defects were detected on CBCT than on periapical radiographs.

CONCLUSIONS

On average, the periapical bone defect measured on periapical radiographs was approximately 10% smaller than on coronally sectioned CBCT images 1 week post-operatively. More remaining defects were detected 1 year after periapical surgery on CBCT images than on periapical radiographs, but it is uncertain how this information is related to success or failure after root-end resection.

Prevalence and incidence of caries lesions in relation to placement and replacement of fillings: a longitudinal observational radiographic study of an adult Danish population

The aim was to describe the prevalence and incidence of caries lesions in relation to the placement and replacement of amalgam and non-metal fillings in a randomly selected adult Danish population. In 1997 and in 2003, 470 individuals underwent a full-mouth radiographic survey. All recordings were based on radiographs. A total of 12,361 teeth were examined. Registrations were performed on surfaces: mesial, distal and occlusal or incisal. In 1997 the total number of teeth and the number of unfilled teeth per individual decreased with the age of the individual, whereas the number of caries lesions per individual did not vary systematically with age. In each age group approximately 50% of the individuals had no caries lesions. In 1997 approximately 70% of the filled surfaces were filled with amalgam and 30% with non-metal filling materials. In 2003 60% of the surfaces were amalgam-filled and 40% were non-metal-filled. Overall non-metal filling material was more frequently used than amalgam in both treatments and re-treatments. During the observation period approximately 20% of both amalgam and non-metal-filled surfaces were re-treated. For amalgam fillings this was constant across the tooth groups, but for non-metal fillings the percentage of re-treated surfaces was larger for molars. The percentage of teeth with caries increased from front teeth to posterior teeth. The lowest percentage of surfaces with caries was detected in unfilled surfaces, and the highest in non-metal-filled surfaces. The results from the present study suggest the need for reflection and diligence when using non-metal materials for dental fillings especially in relation to molars.

Risk factors for developing apical periodontitis in a general population

AIM

To identify and describe individual and tooth-specific factors associated with the incidence or the persistence of apical periodontitis (AP) in a general population.

METHODOLOGY

In 1997, 616 randomly selected individuals had a full-mouth radiographic survey. In 2003, 77% of the participants returned for a new full-mouth radiographic examination. All teeth were assessed individually and data recorded for caries, marginal bone level, and tooth restorations. Multiple logistic regression analyses were performed to identify predictors of AP in the individual. Conditional logistic regression analyses were used to identify risk factors for development of AP in a tooth. Independent variables included a number of individual and tooth-specific variables.

RESULTS

Root fillings, coronal restorations, primary carious lesions, and reduced marginal bone level were associated with the incidence of AP in the individual. In teeth, the quality and presence of a coronal restoration was associated with the incidence of AP, and presence of a root filling also increased the risk of developing AP. Furthermore, an increased risk of developing AP was seen in relation to primary carious lesions, reduced marginal bone level, and molar teeth. The quality of the root filling was not associated with the incidence of AP, but the results suggest an association between the quality of the root filling and the healing of AP.

CONCLUSIONS

Results from the present study demonstrate that it is important to provide high quality dental restorations to minimize the risk of pulpal infection. The clinical focus, in relation to the incidence of AP, should be on improving the quality of the coronal restoration. The quality of a root filling was not associated with the incidence of AP, but may be of importance in relation to healing of AP.

Longitudinal study of periapical and endodontic status in a Danish population

AIM

To describe and discuss changes in periapical and endodontic status in a general Danish population.

METHODOLOGY

In 1997, 616 randomly selected individuals had a full-mouth radiographic survey taken. In 2003, 77% of the participants attended for a new full-mouth radiographic examination. Information on endodontic treatment and periapical status was obtained. The periapical index (PAI) was used to assess apical periodontitis (AP).

RESULTS

More participants had root filling(s) and AP in 2003 than in 1997. More teeth had AP and/or root fillings in 2003. Fewer of the root-filled teeth (RFT) had AP in 2003. Less than 3% of the teeth without root fillings (NRFT) that in 1997 had no AP, developed AP and/or received a root filling. Of the NRFT which in 1997 had AP, more than 35% still had AP and no root filling in 2003. Approximately, 30% of the NRFT with AP in 1997 received a root filling. Of the teeth that received a root filling, 40% had healed, whereas 60% had not. Approximately, 25% of the NRFT that in 1997 had AP had been extracted. In 1997 there were 618 RFT, 314 of the RFT had no AP in 1997. Almost 20% of the RFT that in 1997 were periapically sound, developed AP. Of the 304 RFT with AP in 1997, approximately 30% had healed, in 60% AP persisted, and 10% were extracted.

CONCLUSIONS

The present study indicates that caution must be exercised when statements on the outcome of root canal treatment are made based on the cross-sectional studies.

Students' attitudes to digital radiography and measurement accuracy of two digital systems in connection with root canal treatment

The aim of this study was to evaluate students' attitudes towards digital radiography and measurement accuracy in digital images recorded with a CCD-sensor and a photostimulable phosphor (PSP) plate radiography system in connection with root canal treatment. Thirty-one dental students participated in an endodontic course. Two single-rooted teeth were assigned at random to two receptors for digital radiographic examination, either (i) the RVG-ui CCD sensor or (ii) the Digora PSP plate system. After the endodontic treatment had been completed for the first tooth, the student filled in a questionnaire on their use of the digital system. Thereafter, the students switched radiography system and repeated the procedure for the second tooth. Eventually, the students completed the questionnaire by answering questions that directly compared the two digital systems. The gutta-percha filled tooth was measured using the system's own software. Two measurements of each tooth were performed: total tooth length (TTL) and root filling length (RFL). The teeth were dismounted from the plaster blocks and the true TTL and RFL was measured with an electronic slide calliper. The majority of the students had used the contrast enhancement facility (CCD sensor = 52%, PSP = 71%) and the zoom facility (65-68%) whilst some had used the density enhancement facility (CCD sensor = 39%, PSP = 55%). The students stated that they saved more time when they used the CCD sensor than when they used the PSP system (P < 0.001), and that it was easier to position the tooth with the PSP plate than with the sensor (P < 0.01). The lengths measured on the digital images from both digital systems were marginally larger than the true tooth lengths (P < 0.05). However, there was no difference between the two digital systems for the TTL/RFL ratio (P > 0.05).

A comparison of the quality of root canal treatment in two Danish subpopulations examined 1974-75 and 1997-98

AIM

The aim of this study was to compare the quality of root canal treatment in two Danish subpopulations.

METHODOLOGY

Group 1 (358 patients) was examined 1974-75 and group 2 (244 patients) 1997-98. All patients were more than 20 years old. All had undergone a full-mouth radiographic survey. In root-filled teeth the following parameters were assessed: the quality of the coronal restoration or crown, the lateral seal of the root filling, the length of the root filling, and the periapical status. Chi-squared tests were used for the evaluation of differences between the groups.

RESULTS

In group 1 there were 975 endodontically treated teeth, in group 2 there were 753. In group 1 the majority of root-filled teeth were premolars, in group 2 the majority were molars (P < 0.001). The quality of coronal restorations (P = 0.35) and crowns (P = 0.68) did not differ significantly between the groups. In group 2 more teeth had adequately sealed root canals (P < 0.001) and adequate length of root filling (P < 0.001). More root-filled molar teeth had apical periodontitis (AP) than root-filled premolar and anterior teeth (P < 0.001).

CONCLUSIONS

Whilst the technical quality of endodontic treatment had improved during the last 24 years, basic differences between the populations prevented assessment of the impact of this change on disease frequencies. The study indicates that great care should be taken when comparing different patient populations, in particular more emphasis should be placed on the selection and description of study groups.

Frequency and distribution of endodontically treated teeth and apical periodontitis in an urban Danish population

AIM

The aim of this study was to investigate the prevalence of endodontically treated teeth and apical periodontitis (AP) in a Danish population.

METHODOLOGY

From Aarhus County 614 individuals were radiographically examined, and the frequency of endodontic treatment and periapical status of all teeth were assessed. The year of birth of the subjects ranged from 1935 to 1975. The chi-squared test was used to determine the significance of differences between males and females and amongst age and tooth groups for the following parameters: AP, the number of endodontically treated teeth, and the number of endodontically treated teeth with AP.

RESULTS

A total of 15 984 teeth were examined; of these 538 (3.4%) had AP and 773 (4.8%) had been endodontically treated. Of the endodontically treated teeth, 404 (52.2%) had AP. Females had more endodontically treated teeth than males; otherwise, no effect of gender was observed. Significantly more molars (P < 0.01) had been endodontically treated (8.1%) compared to premolars (5.4%) and anterior teeth (2.5%). The prevalence of AP in connection with molars was significantly (P < 0.01) higher (7.0%) than premolars (2.8%) and anterior teeth (1.5%). The prevalence of endodontically treated teeth and of teeth with AP gradually increased with age.

CONCLUSIONS

The average number of teeth, the number of teeth with AP and the number of teeth with endodontic treatment in Danish adults were comparable to findings in other European countries. The frequency of endodontically treated teeth with AP was found to be high compared to that demonstrated in other epidemiological studies.

Periapical status and quality of root fillings and coronal restorations in a Danish population

AIM

The aim of this study was to investigate the quality of endodontic and coronal restorations and the association with periapical status in a Danish population.

METHODOLOGY

A total of 614 randomly selected individuals (20-60+ years of age) from Aarhus County had a full-mouth radiographic examination. The quality of endodontic and coronal restorations and the periapical status of endodontically treated teeth were assessed by radiographic criteria. Root fillings were categorized as 'adequate' or 'inadequate' with regard to root filling length and lateral seal. Coronal restorations were categorized into 'adequate' and 'inadequate', defined by the absence or presence of radiographic signs of overhangs or open margins. Results were analysed statistically using the chi-squared test.

RESULTS

The total number of endodontically treated teeth was 773, and 52.3% had apical periodontitis (AP). Root-filled teeth with an adequate lateral seal had a lower incidence of AP than teeth with an inadequate seal (44.3% vs. 57.8%), and teeth with an adequate root filling length were associated with a better periapical status than teeth with inadequate length of the root filling (42.0% vs. 67.6%). Similarly, adequate coronal restorations were associated with better periapical status than inadequate restorations (48.0% vs. 63.9%). When both root filling and coronal restoration quality were assessed, the incidence of AP ranged from 31.2% (optimal quality) to 78.3% (all parameters scored as inadequate).

CONCLUSIONS

Inadequate root canal and coronal restorations were associated with an increased incidence of AP.