A strategy for the diagnosis of periapical pathosis

Effectiveness of endodontic complexity assessment tool (E-CAT) on the undergraduate students in an endodontic training program and its predictive capability on complications

INTRODUCTION

Dental students face a number of challenges when it comes to performing root canal treatments (RCTs). The Endodontic Complexity Assessment Tool (E-CAT) was developed to assist dental practitioners in assessing the complexity of RCTs before beginning treatment.

MATERIALS AND METHODS

The E-CAT was filled out independently by both the educator and the student. To allow educators to record scores and complexity classes, they transferred their and students' forms to the website https://www.e-cat.uk/. Students began endodontic treatment after learning about the complexity level of the case. The educators were responsible for recording any complications encountered in every case from the outset to 1 month after treatment.

RESULTS

A total of 70 students, 33 in fourth and 37 in fifth-grade, were included in the study. In the cases with higher E-CAT scores, complications such as misdiagnosed, faulty access cavity, furca or coronal third perforation, insufficient root canal instrumentation, working length loss, canal blockage, overpreparation, incomplete root canal filling and overfilling were experienced significantly more often compared to the cases with lower E-CAT scores (p < .05). The number of complications (r = .40, p < .001), treatment sessions (r = .44, p < .001), and teacher support (r = .24, p < .001) positively correlated with E-CAT score (p < .05).

CONCLUSION

The E-CAT is an effective tool for assisting dental students in understanding technical challenges, such as complex root canal anatomy and possible complications during treatment. Educators can also use e-CAT to pre-select clinical cases and standardise student training by offering cases of equal complexity.

Periradicular repair after single- and two-visit root canal treatments using ultrasonic irrigant activation and calcium hydroxide dressing of teeth with apical periodontitis: study protocol for randomized controlled trials

BACKGROUND

In certain clinical situations, root canal treatment in teeth with apical periodontitis is performed in multiple visits, with the use of intracanal dressing between visits, aiming to reduce microorganisms and their by-products of the root canal system prior to filling. However, in recent years, discussions have been growing about the real need for the use of intracanal dressing in these cases. The use of ultrasonic activation of the auxiliary chemical substance has increased the potential for decontamination promoted during the chemomechanical preparation of the root canal. Thus, this study is designed to explore whether the use of intracanal dressing between visits during endodontic treatment favors periradicular repair in teeth with apical periodontitis.

METHODS

This is a randomized, prospective, double-blinded, controlled clinical trial designed to evaluate 3 distinct clinical approaches used during endodontic therapy: group 1-root canal treatment in a single visit (RCT-SV); group 2-root canal treatment in two visits with intracanal dressing (RCT-TVWD); and group 3-root canal treatment in two visits without intracanal dressing (RCT-TVWOD). A total of 150 adult patients aged 18 to 60, with at least one tooth diagnosed with asymptomatic apical periodontitis and periradicular lesion (confirmed with a cone beam computed tomography (CBCT)), will be randomized and will undergo one of the types of clinical approaches during endodontic therapy. Patients' postoperative pain levels will also be recorded in periods of 24, 48, and 72 h and 7 days. Subsequently, clinical findings and long-term follow-up evaluations, with periradicular repair, will be performed at 6 and 12 months by intraoral periapical radiograph (IOPAR) and CBCT at the 24-month follow-up.

DISCUSSION

This study will evaluate the periradicular repair of mandibular molar teeth with apical periodontitis, providing information about the efficacy, benefits, and safety of performing the endodontic treatment in a single and two visits, with and without the use of calcium hydroxide dressing. All endodontic therapy procedures will be performed under a dental operating microscope and using ultrasonic activation of auxiliary chemical substances. These results may contribute to changes in the clinical approaches adopted during endodontic therapy of teeth with apical periodontitis and reveal the potential of complementary approaches that aim to enhance the decontamination of the root canal system during the preparation stage.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05256667. Registered on 24 February 2022.

Single versus multiple visits for endodontic treatment of permanent teeth

BACKGROUND

Root canal treatment (RoCT), or endodontic treatment, is a common procedure in dentistry. The main indications for RoCT are irreversible pulpitis and necrosis of the dental pulp caused by carious processes, coronal crack or fracture, or dental trauma. Successful RoCT is characterised by an absence of symptoms (i.e. pain) and clinical signs (i.e. swelling and sinus tract) in teeth without radiographic evidence of periodontal involvement (i.e. normal periodontal ligament). The success of RoCT depends on a number of variables related to the preoperative condition of the tooth, as well as the endodontic procedures. RoCT can be carried out with a single-visit approach, which involves root canal system obturation (filling and sealing) directly after instrumentation and irrigation, or with a multiple-visits approach, in which the treatment is completed in two or more sessions and obturation is performed in the last session. This review updates the previous versions published in 2007 and 2016.

OBJECTIVES

To evaluate the benefits and harms of completion of root canal treatment (RoCT) in a single visit compared to RoCT over two or more visits, with or without medication, in people aged over 10 years.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 25 April 2022.

SELECTION CRITERIA

We included randomised controlled trials and quasi-randomised controlled trials in people needing RoCT comparing completion of RoCT in a single visit compared to RoCT over two or more visits.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. tooth extraction and 2. radiological failure after at least one year (i.e. periapical radiolucency). Our secondary outcomes were 3. postoperative and postobturation pain; 4. swelling or flare-up; 5. analgesic use and 6. presence of sinus track or fistula after at least one month. We used GRADE to assess certainty of evidence for each outcome. We excluded five studies that were included in the previous version of the review because they did not meet the current standard of care (i.e. rubber dam isolation and irrigation with sodium hypochlorite).

MAIN RESULTS

We included 47 studies with 5805 participants and 5693 teeth analysed. We judged 10 studies at low risk of bias, 17 at high risk of bias and 20 at unclear risk of bias. Only two studies reported data on tooth extraction. We found no evidence of a difference between treatment in one visit or treatment over multiple visits, but we had very low certainty about the findings (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.09 to 2.50; I2 = 0%; 2 studies, 402 teeth). We found no evidence of a difference between single-visit and multiple-visit treatment in terms of radiological failure (RR 0.93, 95% CI 0.81 to 1.07; I2 = 0%; 13 studies, 1505 teeth; moderate-certainty evidence). We found evidence of a higher proportion of participants reporting pain within one week in single-visit groups compared to multiple visit groups (RR 1.55, 95% CI 1.14 to 2.09; I2 = 18%; 5 studies, 638 teeth; moderate-certainty evidence).  We found no evidence of a difference in the proportion of participants reporting pain until 72 hours postobturation (RR 0.97, 95% CI 0.81 to 1.16; I2 = 70%; 12 studies, 1329 teeth; low-certainty evidence), pain intensity until 72 hours postobturation (mean difference (MD) 0.26, 95% CI -4.76 to 5.29; I2 = 98%; 12 studies, 1258 teeth; low-certainty evidence) or pain at one week postobturation (RR 1.05, 95% CI 0.67 to 1.67; I2 = 61%; 9 studies, 1139 teeth; very low-certainty evidence). We found no evidence of a difference in swelling or flare-up incidence (RR 0.56 95% CI 0.16 to 1.92; I2 = 0%; 6 studies; 605 teeth; very low-certainty evidence), analgesic use (RR 1.25 95% CI 0.75 to 2.09; I2 = 36%; 6 studies, 540 teeth; very low-certainty evidence) or sinus tract or fistula presence (RR 1.00, 95% CI 0.24 to 4.28; I2 = 0%; 5 studies, 650 teeth; very low-certainty evidence). Subgroup analysis found no differences between single-visit and multiple-visit RoCT for considered outcomes other than proportion of participants reporting post-treatment pain within one week, which was higher in the single-visit groups for vital teeth (RR 2.16, 95% CI 1.39 to 3.36; I2 = 0%; 2 studies, 316 teeth), and when instrumentation was mechanical (RR 1.80, 95% CI 1.10 to 2.92; I2 = 56%; 2 studies, 278 teeth).

AUTHORS' CONCLUSIONS

As in the previous two versions of the review, there is currently no evidence to suggest that one treatment regimen (single-visit or multiple-visit RoCT) is more effective than the other. Neither regimen can prevent pain and other complications in the 12-month postoperative period. There was moderate-certainty evidence of higher proportion of participants reporting pain within one week in single-visit groups compared to multiple-visit groups. In contrast to the results of the last version of the review, there was no difference in analgesic use.

Is periapical surgery follow-up with only two-dimensional radiographs reliable? A retrospective cohort type sensitivity study

Background

Two-dimensional (2D) radiographic techniques are commonly used for assessing lesion prognosis after endodontic surgery. The present retrospective cohort study analyzes the sensitivity and ability of different radiographic techniques in obtaining area and volume measurements of periapical lesions.

Material and Methods

Preoperative and follow-up (6-48 months) periapical and panoramic radiographs (index test) and cone-beam computed tomography (CBCT) images (reference standard) were selected from an endodontic microsurgery database. Sensitivity was analyzed independently by two examiners. The areas of the 2D radiographic images and CBCT volumes were studied using Itk-Snap software and Romexis viewer.

Results

The sample comprised 105 patients and 105 teeth, with a mean follow-up of 21 months (range 6-48). Preoperatively, CBCT detected all the periapical areas, periapical radiography detected 67, and panoramic radiography detected 60. Postoperatively, of the 52 cases in which CBCT detected remains of the periapical area, periapical radiography detected 22, and panoramic radiography detected 17. The measurements of the areas obtained by the 2D methods, and the volumes obtained by CBCT, had to be transformed into linear measures for comparison purposes. The measurements were found to be significantly different in both the preoperative and the follow-up images.

Conclusions

 Periapical radiography showed greater sensitivity than panoramic radiography, both preoperatively and at follow-up. The lesions measured with CBCT were larger, with significant differences than as evidenced by the periapical and panoramic radiographs.

Key words:Periapical radiography, panoramic radiography, CBCT, sensitivity, treatment outcome, size of periapical radiolucency, area, volume.

Evaluation of Healing of Periapical Tissue in Permanent Incisors with Open Apices after Unintentional Extrusion of Mineral Trioxide Aggregate - A Retrospective Study

Aim

The aim of the present study was to retrospectively assess the healing of periapical lesions in permanent central incisors with open apices after unintentional extrusion of mineral trioxide aggregate (MTA).

Materials and Methods

The clinical and radiographic records of 75 maxillary permanent central teeth treated by MTA apexification were evaluated. Teeth with unintentionally extruded MTA formed the study group (Group 1, n = 28), whereas the teeth with no MTA extrusion formed the control group (Group 2, n = 47). For both the groups, the records were analyzed for a follow-up period of 3 years.

Results

Complete healing (CH) was observed in 25 teeth in the study group, whereas all the teeth in the control group showed CH (P > 0.05). Within the study group, 6 teeth (21%) showed CH in the 6^th month in Group 1, whereas in the control group, 34 teeth (72.3%) showed CH (P < 0.001). At the 1-year follow-up appointment, 19 teeth (67.8%) showed CH in Group 1, whereas 9 teeth (19.1%) showed the same result in Group 2 (P < 0.001). At the end of the 3-year follow-up period, it was noticed that in 21 (84%) teeth, extruded MTA remained unchanged, whereas it was reduced in 4 (16%) of them (P < 0.001).

Conclusion

Extrusion of MTA does not have a significant effect on the healing of the periapical lesion. However, it may lead to a delay in the healing of periapical healing. Patients should be informed about the complication and consequences of extruded MTA and should be kept on follow-up to observe periapical healing.

Increased Plasma Osteocalcin, Oral Disease, and Altered Mandibular Bone Density in Postmenopausal Women

An association between oral diseases and postmenopausal status has been recognized. However, the relationship between all oral disease, mandibular bone density, health status, and osteocalcin (OCN) bone markers in postmenopausal dental patients has not been reported. This study was therefore to verify the differences in plasma OCN levels, dental, periodontal, and oral mucosal disease, and mandibular bone density alterations from panoramic radiograph and systemic parameters in postmenopausal women, compared to premenopausal women. Oral, radiographic, and blood examination were performed in 92 females. Dental, periodontal, and oral mucosal statuses were recorded. Health profile parameters were collected from medical charts. Plasma OCN was evaluated by enzyme-linked immunosorbent assay. Forty-two (45.7%) participants were postmenopausal with a higher median age (55 (51, 62) years) than the premenopausal group (43 (38, 45) years). Overweight or obesity, hypercholesterolemia, and impaired fasting blood sugar were more prevalent in postmenopause. The average postmenopausal OCN level (425.62 ng/mL) was significantly higher than the premenopausal group (234.77 ng/mL, p < 0.001). The average number of missing teeth, mean attachment loss, alveolar bone loss, periapical lesion count, and clinical oral dryness score were also significantly higher in postmenopause (p=0.008,   < 0.001,  0.031,  0.006,  and 0.005, respectively). However, mandibular bone density determined by mandibular cortical index was lower in postmenopause (p < 0.001). The panoramic mandibular index, mandibular cortical width, fractal dimension, and other oral mucosal disease did not differ between the groups. Postmenopause was associated with elevated plasma OCN (β = 0.504, p < 0.001) when related covariates were adjusted. Elevated plasma OCN, oral mucosal dryness, high number of periapical radiolucencies and missing teeth, and lower mandibular bone density from panoramic radiograph were prevalent in postmenopausal women. Dentists should suspect an increased risk of low bone mineral density in postmenopausal patients who display these clinical and radiographic findings, and they should be referred for further examination. Plasma OCN may interconnect a relationship between postmenopausal status and the low mandibular bone density.

Retrospective evaluation of healing of periapical lesions after unintentional extrusion of mineral trioxide aggregate

BACKGROUND

During the apexification procedure for teeth with open apices, mineral trioxide aggregate (MTA) may be unintentionally extruded. The aim of the present study was the retrospective evaluation of the healing of periapical lesions in permanent incisor teeth with open apices after the unintentional extrusion of MTA.

METHODS

The clinical and radiographic records of 55 maxillary permanent central teeth treated by MTA apexification were evaluated. Filled teeth with unintentionally extruded MTA were selected as group 1 (n = 21), whereas the teeth with no MTA extrusion were selected as group 2 (n = 34). For each tooth, the clinical and radiographic records from a 3-year follow-up were investigated.

RESULTS

Complete healing (CH) was observed in 19 teeth (90.4%) in group 1, whereas the same type of healing was observed in all 34 teeth (100%) in group 2 (p>0.05). At the 6-month follow-up appointment, 25 teeth (73.5%) showed CH in group 2, whereas 15 teeth (71.4%) showed CH at the 1-year follow-up in group 1 (p<0.001). At the end of the 3-year follow-up period, the amount of MTA extrusion was reduced in 17 teeth (85%) (p<0.05), whereas it was almost absent in 2 teeth (10%).

CONCLUSIONS

The unintentional extrusion of MTA does not prevent the healing of periapical lesions, but may be a delaying factor for periapical healing.

Definitions and Epidemiology of Endodontic Infections

Purpose of Review

This review describes the recent findings from epidemiological studies on endodontic infections. The recent literature was screened for studies on the prevalence of primary apical periodontitis and posttreatment apical periodontitis in various populations.

Recent Findings

Twenty-nine articles reporting data on the prevalence of primary or posttreatment apical periodontitis from all over the world were included. The prevalence of apical periodontitis varied between 7 and 86%, while that of posttreatment apical periodontitis varied between 10 and 62%. The quality of the coronal restoration and the root filling appears to be the major predictors of apical periodontitis.

Summary

The recent findings from epidemiological studies on the prevalence of primary and posttreatment apical periodontitis in various populations are not substantially different from those from earlier years. It appears that the health of periapical tissues has not majorly improved in the general population.

Single versus multiple visits for endodontic treatment of permanent teeth

BACKGROUND

Root canal treatment (RoCT), or endodontic treatment, is a common procedure in dentistry. The main indications for RoCT are irreversible pulpitis and necrosis of the dental pulp caused by carious processes, tooth cracks or chips, or dental trauma. Successful RoCT is characterised by an absence of symptoms (i.e. pain) and clinical signs (i.e. swelling and sinus tract) in teeth without radiographic evidence of periodontal involvement (i.e. normal periodontal ligament). The success of RoCT depends on a number of variables related to the preoperative condition of the tooth, as well as the endodontic procedures. This review updates the previous version published in 2007.

OBJECTIVES

To determine whether completion of root canal treatment (RoCT) in a single visit or over two or more visits, with or without medication, makes any difference in term of effectiveness or complications.

SEARCH METHODS

We searched the following electronic databases: Cochrane Oral Health's Trials Register (to 14 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 5), MEDLINE Ovid (1946 to 14 June 2016), and Embase Ovid (1980 to 14 June 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials to 14 June 2016. We did not place any restrictions on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs of people needing RoCT. We excluded surgical endodontic treatment. The outcomes of interest were tooth extraction for endodontic problems; radiological failure after at least one year, i.e. periapical radiolucency; postoperative pain; swelling or flare-up; painkiller use; sinus track or fistula formation; and complications (composite outcome including any adverse event).

DATA COLLECTION AND ANALYSIS

We collected data using a specially designed extraction form. We contacted trial authors for further details where these were unclear. We assessed the risk of bias in the studies using the Cochrane tool and we assessed the quality of the body of evidence using GRADE criteria. When valid and relevant data were collected, we undertook a meta-analysis of the data using the random-effects model. For dichotomous outcomes, we calculated risk ratios (RRs) and 95% confidence intervals (CIs). For continuous data, we calculated mean differences (MDs) and 95% CIs. We examined potential sources of heterogeneity. We conducted subgroup analyses for necrotic and vital teeth.

MAIN RESULTS

We included 25 RCTs in the review, with a total of 3780 participants, of whom we analysed 3751. We judged three studies to be at low risk of bias, 14 at high risk, and eight as unclear.Only one study reported data on tooth extraction due to endodontic problems. This study found no difference between treatment in one visit or treatment over multiple visits (1/117 single-visit participants lost a tooth versus 2/103 multiple-visit participants; odds ratio (OR) 0.44, 95% confidence interval (CI) 0.04 to 4.78; very low-quality evidence).We found no evidence of a difference between single-visit and multiple-visit treatment in terms of radiological failure (risk ratio (RR) 0.91, 95% CI 0.68 to 1.21; 1493 participants, 11 studies, I² = 18%; low-quality evidence); immediate postoperative pain (dichotomous outcome) (RR 0.99, 95% CI 0.84 to 1.17; 1560 participants, 9 studies, I² = 33%; moderate-quality evidence); swelling or flare-up incidence (RR 1.36, 95% CI 0.66 to 2.81; 281 participants, 4 studies, I² = 0%; low-quality evidence); sinus tract or fistula formation (RR 0.98, 95% CI 0.15 to 6.48; 345 participants, 2 studies, I² = 0%; low-quality evidence); or complications (RR 0.92, 95% CI 0.77 to 1.11; 1686 participants, 10 studies, I² = 18%; moderate-quality evidence).The studies suggested people undergoing RoCT in a single visit may be more likely to experience pain in the first week than those whose RoCT was over multiple visits (RR 1.50, 95% CI 0.99 to 2.28; 1383 participants, 8 studies, I² = 54%), though the quality of the evidence for this finding is low.Moderate-quality evidence showed people undergoing RoCT in a single visit were more likely to use painkillers than those receiving treatment over multiple visits (RR 2.35, 95% CI 1.60 to 3.45; 648 participants, 4 studies, I² = 0%).

AUTHORS' CONCLUSIONS

There is no evidence to suggest that one treatment regimen (single-visit or multiple-visit root canal treatment) is better than the other. Neither can prevent all short- and long-term complications. On the basis of the available evidence, it seems likely that the benefit of a single-visit treatment, in terms of time and convenience, for both patient and dentist, has the cost of a higher frequency of late postoperative pain (and as a consequence, painkiller use).

Influence of increased patient age on longitudinal outcomes of root canal treatment: a systematic review

OBJECTIVES

To conduct a systematic review of longitudinal endodontic outcomes in elders.

BACKGROUND

Negative opinions about the prognosis of non-surgical root canal treatment (NSRCT) in elders affect decisions made by patients and dentists. Patient, caregiver and dentist attitudes and behaviours may interact to decrease the provision of NSRCT. Critical examination of the available evidence through systematic review could provide objective data to assist patients, caregivers, healthcare providers and third-party payers in making decisions about the efficacy of NSRCT in elders and provide a robust foundation for the health promotion of NSRCT in elders.

METHODS

Inclusion/exclusion criteria were used for defined searches in MEDLINE and Cochrane CENTRAL. Title lists were scanned, and abstracts read to determine utility; articles meeting inclusion/exclusion criteria were analysed. Data were extracted and compiled into a table of evidence.

RESULTS

Defined searching produced 3605 titles; 24 articles were included, nine prospective and 15 retrospective. Overall study quality was good. Patient samples mostly represented modern populations from countries with very high human development indices. Over 17 430 teeth were included. Meta-analysis was not attempted due to heterogeneity in reporting. All 24 included papers demonstrated that increased patient age did not decrease the success or survival rates of NSRCT.

CONCLUSIONS

This systematic review of longitudinal NSRCT outcomes demonstrated that increased patient age did not decrease the success of NSRCT. Patient age is not a prognostic factor for NSRCT. Age should not be considered by dentists or patients when making NSRCT decisions.

A recall program for the outcome of conventional root canal treatment performed in a teaching hospital

OBJECTIVES

This study investigated the long-term survival and the prognostic factors of endodontic treatments performed in a dental teaching hospital. The aim was to calculate the probabilities of success or failure according to the follow-up extent and to assess the time allowed for a complete periapical healing.

MATERIALS AND METHODS

A cohort of 185 teeth were re-examined 1-4 years after treatment. The outcome was assessed on the basis of radiographic and clinical criteria as success, uncertain or failure. A survival analysis using the Cox model was used (i) to explore tooth survival and periapical healing over the time and (ii) to highlight the predictive factors of treatment outcome.

RESULTS

After 2 years, the appearance of an apical periodontitis remained lower than 3.5%, whereas only 22.8% of periapical healed cases were notified. The prognosis factors are: (i) for teeth with initial healthy periapical conditions, coronal leakage (p = 0.002) with the higher risk of failure (RR = 19.77), absence of correspondence filling length/shaping = 0.026), type of teeth (p = 0.041) and (ii) for teeth with apical periodontitis, number of root canals (p = 0.000,91), correspondence filling length/shaping length (p = 0.017) and over-filling (p = 0.09). New periapical lesions or tooth loss were recorded after 2 years. Half of the successful cases of periapical healing were observed during the follow-up from 2-4 years.

CONCLUSIONS

This longitudinal study shows that coronal leakage is responsible for late failure and that periapical healing is long to achieve. Therefore, endodontic treatments may require a follow-up of over 2 years.

Radiolucent periapical lesions and bone mineral density in post-menopausal women

PURPOSE

To investigate the relationship between radiolucent periapical lesions and bone mineral density in post-menopausal women.

MATERIAL AND METHODS

Seventy-five post-menopausal women were recruited for the study. Bone mineral density was measured using dual-energy X-ray absorptiometry. Three groups were established: healthy bone group, osteopenic group and osteoporotic group. Periapical radiolucencies were diagnosed on the basis of examination of digital panoramic radiographs. Statistical analysis was carried out using anova and chi-squared tests, and logistic regression analysis.

RESULTS

In both the osteopenic and osteoporotic groups, 25% of women showed at least one periapical radiolucency, whereas this was only 7.4% in the healthy bone group (odds ratio = 4.2; p = 0.061). After multivariate logistic regression analysis adjusting for covariates (age, number of teeth, number of root-filled teeth and number of teeth with coronal restorations), a marginally significant association was evident between bone mineral density and the presence of periapical radiolucencies (odds ratio = 1.9; CI 95% = 1.0-3.8; p = 0.050).

CONCLUSIONS

After adjusting for covariates, low bone mineral density is marginally associated with a higher frequency of radiolucent periapical lesions.

Instrument fracture in root canals - where, why, when and what? A study from a student clinic

AIM

To investigate the incidence of instrument fracture during nonsurgical root canal treatment performed by undergraduate dental students and to assess the outcome of the treatment if the remaining fragment was left or removed from the root canal.

METHODOLOGY

A retrospective analysis was performed by reviewing assessment forms (n = 3854) filled out for each root canal treatment over a 10-year period (1997-2006) at the University of Bergen, Norway. Based on the assessment forms, all instrument fractures and data concerning type and dimension of the fractured instruments were identified. Moreover, the affected tooth, root, root curvature and the vertical level of the fragment in the root canal were recorded. To assess the outcome of the root canal treatment, radiographs taken at follow-ups were evaluated by two individual examiners.

RESULTS

The overall incidence of instrument fracture during the period was 1.0% on a tooth level. Instrument fracture occurred significantly more often in molars and in teeth rated as difficult preoperatively. Of all instrument fractures, 39.5% were located in the mesio-buccal canals of molars, and 76.5% of the fragments were located apically. A significant high percentage of instruments of small apical diameter (sizes 006-015) fractured in relative straight root canals. The treatment was successful in 71.4% of the cases where the instrument fragment was removed, but only in 56.5% of the cases where the fragment remained in the root canal. Significantly more instruments were removed from teeth with a primary infection (P ≤ 0.05). The success rate for teeth with instrument fracture was 72.7% for vital teeth, 58.3% for primary infected teeth and 42.9% in retreatment cases.

CONCLUSIONS

Within the limits of the present study, the results indicate that the preoperative diagnosis is important for the final treatment outcome and that removal of the fragment is important in cases with primary infection.

Comparison of cone-beam computed tomography and periapical radiography in predicting treatment decision for periapical lesions: a clinical study

Objectives. To compare the ability of endodontists to determine the size of apical pathological lesions and select the most appropriate choice of treatment based on lesions' projected image characteristics using 2 D and 3 D images. Study Design. Twenty-four subjects were selected. Radiographic examination of symptomatic study teeth with an intraoral periapical radiograph revealed periapical lesions equal to or greater than 3 mm in the greatest diameter. Cone-beam Computed tomography (CBCT) images were made of the involved teeth after the intraoral periapical radiograph confirmed the size of lesion to be equal to greater than 3 mm. Six observers (endodontists) viewed both the periapical and CBCT images. Upon viewing each of the images from the two imaging modalities, observers (1) measured lesion size and (2) made decisions on treatment based on each radiograph. Chi-square test was used to look for differences in the choice of treatment among observers. Results. No significant difference was noted in the treatment plan selected by observers using the two modalities (χ²(3) = .036, P > 0.05). Conclusion. Lesion size and choice of treatment of periapical lesions based on CBCT radiographs do not change significantly from those made on the basis of 2 D radiographs.

Polymerase chain reaction of enterococcus faecalis and candida albicans in apical periodontitis from Turkish patients

Aim: The aim of this study was to determine the frequency of two important pathogenic microorganisms associated with endodontic infections, Enterococcus faecalis and Candida albicans, in root canal samples from patients with necrotic pulps or failed canal therapy by polymerase chain reaction method. Method: Microbial samples were obtained from 117 teeth with necrotic pulp tissues and 114 teeth with failed endodontic treatment. Results: E.faecalis were identified in 16% of the necrotic and 10% of the retreated root canal infections by PCR. C.albicans genome were identified in 20% and 11% of the necrotic and retreated root canal infections, respectively, by PCR. The frequencies of microbiota were not statistically different between necrotic and retreatment groups (p > 0.05, chi squared test). Conclusions: PCR analysis of teeth with periapical lesions revealed that E.faecalis was found in fewer patients than in previous studies. The C.albicans prevelance was consistent with previous reports. No statistical difference was found between primary and secondary root canal infections for C.albicans or E.faecalis.

Key words:Primary root canal infection, secondary root canal infection, E.faecalis, C.albicans.

Pre-operative diagnostic radiograph interpretation by general dental practitioners for root canal treatment

OBJECTIVES

The aim of this study was to evaluate which radicular radiographic features general dentists want to interpret, determine which of the radicular radiographic features general dentists interpret and which ones they miss in a diagnostic radiograph and correlate how accurately general dentists are able to interpret radiographic features.

METHODS

20 general dental practitioners were selected and given 2 sets of questionnaires. The first set asked them to fill out the findings they would elucidate in a diagnostic radiograph while the second set consisted of 30 randomly selected intraoral radiographs to interpret.

RESULTS

In the first set of questionnaires, more than 50% of dentists said they would interpret periapical changes, calcification, root curvature and the number of root canals. Less than 50% said they would interpret canal morphology, open apex, resorption, fracture, number of roots and lamina dura. In the second set of questionnaires, more than 90% missed grade 1 or 2 periapical changes (according to periapical index scoring), resorption and canal calcification. More than 80% of dentists missed extra roots and root curvature buccally while no dentists were able to interpret the periodontal ligament width changes, lamina dura and canal variation (C-shape). Using a paired t-test, there was significant variation in answers between the first set and second set of questionnaires.

CONCLUSION

It is concluded from this study that general dental practitioners are able to detect radiographic changes when they are extensive but they miss periodontal ligament width and lamina dura changes.

Effect of guided tissue regeneration on the outcome of surgical endodontic treatment of through-and-through lesions: a retrospective study at 4-year follow-up

PURPOSE

The main purpose of this retrospective cohort study was to evaluate the 4-year success rate of endodontic surgery in combination with a collagen resorbable membrane for the treatment of through-and-through periradicular lesions.

MATERIALS AND METHODS

Patients with one or more teeth with a through-and-through periradicular lesion in need of endodontic surgery were treated. A clinical and radiographic evaluation was performed at 3, 6, 12, 24, 36, and 48 months. The outcome was categorized at 1 and 4-year follow-up as success, failure, and doubtful depending on clinical signs and symptoms and radiographic evaluation. Fisher's exact test was used to evaluate differences between successful and failed cases (P < 0.05).

RESULTS

Forty-three teeth in 33 patients were radiographically and clinically evaluated after 4 years. Thirty-eight teeth were classified as success, 4 teeth as failure, and 1 tooth as doubtful. No statistically significant differences were found in results related to tooth type, tooth location, and presence of post.

CONCLUSIONS

The association of endodontic surgery and guided tissue regeneration for the treatment of through-and-through periapical lesions leads to excellent outcomes up to 4 years. Standardized criteria are needed to determine the treatment outcome.

A new periapical index based on cone beam computed tomography

The purpose of this study was to evaluate a new periapical index based on cone beam computed tomography (CBCT) for identification of apical periodontitis (AP). The periapical index proposed in this study (CBCTPAI) was developed on the basis of criteria established from measurements corresponding to periapical radiolucency interpreted on CBCT scans. Radiolucent images suggestive of periapical lesions were measured by using the working tools of Planimp software on CBCT scans in 3 dimensions: buccopalatal, mesiodistal, and diagonal. The CBCTPAI was determined by the largest lesion extension. A 6-point (0-5) scoring system was used with 2 additional variables, expansion of cortical bone and destruction of cortical bone. A total of 1014 images (periapical radiographs and CBCT scans) originally taken from 596 patients were evaluated by 3 observers by using the CBCTPAI criteria. AP was identified in 39.5% and 60.9% of cases by radiography and CBCT, respectively (P < .01). The CBCTPAI offers an accurate diagnostic method for use with high-resolution images, which can reduce the incidence of false-negative diagnosis, minimize observer interference, and increase the reliability of epidemiologic studies, especially those referring to AP prevalence and severity.

Endodontic treatment outcome: effect of the permanent restoration

OBJECTIVE

To investigate the relationship between the presence of the coronal restoration and endodontic treatment success or failure.

METHODS

This study comprised 200 endodontically treated teeth with 441 roots. Follow-up examination was conducted 4 +/- 0.5 years after completion of endodontic treatment. Outcome criteria were modified from Strindberg.

RESULTS

Teeth/roots restored with permanent coronal restoration (casting or filling) had a higher success rate (80%) than teeth/roots not restored (60%; P < .01) in the analysis of aggregate data. However, the results of stratified analysis on key confounding factor (preoperative periapical diagnosis) showed that there is no significant association between the presence of permanent restoration and endodontic outcome. Teeth with preoperative apical periodontitis were less likely to be restored with a crown (23.9%) than teeth without apical periodontitis (76.1%; P < .01). Anterior teeth were more likely to be restored with a filling and sooner than the posterior teeth. These associations suggest a treatment selection bias.

CONCLUSIONS

Stratified analysis on the key confounding factor reveals that endodontic outcome is driven by the presence of preoperative root canal infection (apical periodontitis). Lack of stratification on key confounding factors inaccurately suggests that presence of permanent restoration contributes to the success of endodontic treatment in the aggregate analysis of grouped data. The choice to restore the tooth as well as the choice and timing of permanent restoration may be the result of a bias in treatment selection. Stratified analysis on key confounding factors is the key to valid analysis and accurate results.

Radiographic evaluation of periapical healing of permanent teeth with periapical lesions after extrusion of AH Plus sealer

The aim of this study was to clinically and radiographically examine the effects of extrusion of AH Plus sealer on the healing of permanent teeth with apical periodontitis. A total of 87 root canals radiographically detected with apical periodontitis were included in the study. Posttreatment radiographs indicated sealer extrusion into 49 canals (Group 1) and no sealer extrusion into 38 canals (Group 2). Periapical treatment was judged as complete healing (CH), incomplete healing (IH) and no healing (NH) at the end of a 4-year follow-up period. Amounts of extraradicular sealer were recorded as "unchanged," "reduced," "almost absent," or "absent." The t test was used for the statistical analyses. In Group 1, CH was detected in 41 canals, IH in 4 canals, and NH in 4 canals. Differences between CH and both IH and NH were statistically significant (P < .001). In Group 2, CH was detected in 34 canals and NH in 4 canals. The difference between CH and NH was statistically significant (P < .001). A statistically significant difference (P < .05) between treatment groups was observed for CH at the 6-month follow-up appointment only; other than that instance, there were no statistical differences for CH or NH between the groups. In conclusion, extruded AH Plus does not prevent periapical healing, but can be a delaying factor for healing in children.

Comparing the accuracy of panoramic and intraoral radiography in the diagnosis of proximal caries

OBJECTIVES

The purpose of this study was to compare the diagnostic accuracy of panoramic and intraoral radiographic surveys in the diagnosis of proximal caries according to the different dental regions (maxillary and mandibular incisor, canine, premolar and molar).

METHODS

In this study, full mouth series and panoramic radiographs of 79 patients were used. The radiographs were evaluated for proximal caries by three observers. The diagnostic accuracy of radiographic surveys for each dental region was assessed by means of receiver operating characteristic (ROC) curve analysis.

RESULTS

Full mouth series was the most efficient method in the diagnosis of caries for incisor and canine teeth. However, full mouth series and combination of panoramic plus bitewings had similar diagnostic accuracy for premolar and molar teeth.

CONCLUSIONS

Panoramic survey alone was not sufficient for the diagnosis of proximal caries for the entire dentition. The combination of panoramic plus bitewing plus anterior periapical survey exhibited a diagnostic accuracy for proximal caries that was comparable with full mouth series.

Nonsurgical retreatment of teeth with periapical lesions previously managed by either endodontic or surgical intervention

OBJECTIVE

The purpose of this study was to evaluate the outcome of nonsurgical retreatment of teeth with periapical lesions, which had been previously managed by either endodontic or surgical intervention, and to identify factors that might influence the prognosis.

STUDY DESIGN

Seventy-five endodontically and 11 surgically treated teeth with persisting periapical lesions ranging in size from 2 to 11 mm in diameter were included in this study. The teeth were nonsurgically retreated, using calcium hydroxide as intracanal medicament, and were followed for a period of 2 to 8 years.

RESULTS

Clinical and radiographic assessment of retreatment showed that complete healing for all cases was 61.6% with an additional category of incomplete healing of 14%; 24.4% failed. The size of the periapical lesions and previous surgical treatment had marginally negative influences on the prognosis, but the differences were not statistically significant.

CONCLUSION

The favourable results of this study demonstrated that nonsurgical root canal retreatment is an alternative to surgical intervention of postendodontic or postsurgical failure.

Endodontic surgery with ultrasonic retrotips: One-year follow-up

OBJECTIVE

The purpose of this prospective clinical study was to monitor the outcome of ultrasonic root-end preparation, in relation to tooth type and location, presence of post restoration and type of retrotip.

STUDY DESIGN

Teeth treated surgically showed a periradicular lesion of strictly endodontic origin. Fifty teeth were included in the study, according to specific selection criteria. Cases were followed for a period of 1 year and then classified in 3 groups (success, uncertain healing, and failure) according to radiographic and clinical criteria.

RESULTS

Of the 46 teeth evaluated at 1-year follow-up, 42 teeth (91.3%) successfully healed, 1 tooth had uncertain healing, and 3 failed. We found no statistically significant differences in treatment results related to the type of tooth, tooth location, post restoration, and type of retrotip.

CONCLUSION

Adherence to a strict endodontic surgical protocol and the use of contemporary techniques and materials can lead to a predictable outcome.

Levels of evidence for the outcome of endodontic surgery

The purpose of this investigation was twofold: (1) to search for clinical articles pertaining to success and failure of periapical surgery and (2) to assign levels of evidence to these studies except case reports. Electronic and manual searches were conducted to identify all the literature regarding success and failure of periapical surgery since 1970. Articles were reviewed, and each article was assigned to a level of evidence from 1 (highest level) to 5 (lowest level). This search located 79 clinical studies. Among these studies, there were no level of evidence-1 randomized clinical trial studies. Five of the seven level of evidence-2 randomized clinical trials compared postoperative pain between surgical and nonsurgical retreatment. Only two level of evidence-2 randomized clinical trials compared the outcomes of surgical treatment with that of nonsurgical treatment. The majority of frequently quoted "success and failure" studies were case series (level of evidence 4).

Increased width of the apical periodontal membrane space in endodontically treated teeth may represent favourable healing

AIM

To examine cases showing increased width of the periodontal space (IW) at a long-term follow-up examination and to determine whether this finding could be explained by endodontic or nonendodontic factors.

METHODOLOGY

A series of intraoral radiographs was obtained from 131 patients 20-27 years after root canal treatment. The same individuals had been examined 10 years earlier, and radiographs taken immediately after treatment were also available. Fourteen roots (5.6%) demonstrated increased width of the apical periodontal space at the end of the study period. These were subjected to further analysis in an attempt to disclose possible explanatory factors.

RESULTS

Two of the 14 cases had reduced marginal bone levels interpreted as the origin of the IW. In three cases, overextended root filling material present 10 years earlier had disappeared and the persistent IW was interpreted as representing a remodelling process. In six cases the findings were explained as being caused by physical and anatomical factors that represented healing without complete re-formation of the apical periodontal structures, or both. Three cases were judged as unfavourable, on the basis of lacking progress in healing, unsatisfactory obturation of the apical portion of the root canal or dentine resorption close to the apical end of the root filling.

CONCLUSION

Most of the 14 IW cases examined after 20-27 years could be explained by reduced marginal bone support, or by physical and anatomical factors or they might represent incomplete reformation of the typical apical morphology and were thereby recorded as favourable outcomes.

Digital Radiograph Registration and Subtraction: A Useful Tool for the Evaluation of the Progress of Chronic Apical Periodontitis

The purpose of this study was to evaluate the suitability of a digital radiograph registration and subtraction software for a sensitive and reliable assessment of the progress of chronic apical periodontitis. Ninety cases of teeth with chronic apical periodontitis have been studied. In each case, a preoperative radiograph was taken, root canals were prepared, and a Ca(OH)2 paste was placed in the root canals. Radiographic control and replacement of Ca(OH)2 paste took place at 15-day intervals. The root canals were obturated 1.5 months after the first appointment. Recall radiographs were taken 0.5, 1.5, 3, 6, and 12 months after the obturation. All radiographs were taken for each case under constant conditions by using a direct digital radiography system. In each case, the preoperative, postoperative, and control and recall radiographs were digitally registered and pairwise subtracted. The resulting images were further processed by using contrast enhancement and pseudocoloring methods. Changes to the periapical tissue structure were easily detectable by using the above-mentioned methodology, even during short time intervals.

Prognosis of large cyst-like periapical lesions following nonsurgical root canal treatment: a clinical review

AIM

To evaluate clinically and radiographically the long-term clinical outcome of nonsurgical root canal treatment using calcium hydroxide in teeth with large cyst-like periapical lesions.

SUMMARY

A total of 42 mature anterior teeth with large periapical lesions ranging in size from 7 to 18 mm in diameter were included in this study. Fluid samples from the lesions contained cholesterol crystals, which were identified by light microscopy. After adequate draining, the teeth were treated endodontically using calcium hydroxide as the intracanal medicament. All cases were followed up for a period of 2-10 years. Complete healing was observed in 73.8% and incomplete healing in a further 9.5% of cases.

KEY LEARNING POINTS

Root canal treatment using calcium hydroxide as an antibacterial dressing was successful in healing large cyst-like periapical lesions. This study suggests that the size of a periapical lesion is not a major determining factor in the decision to perform conventional root canal treatment or surgical removal of the lesion. Even large cyst-like periapical lesions containing cholesterol crystals can heal following nonsurgical root canal treatment.

Nonsurgically retreated root filled teeth--radiographic findings after 20-27 years

AIM

To identify periapical changes in nonsurgically retreated root-filled teeth 20-27 years after root canal treatment.

METHODOLOGY

From an original material of 429 roots, retreated by undergraduate students in a teaching clinic, 112 roots in 70 individuals could be evaluated radiographically 20-27 years after treatment. The same roots had been studied 10-17 years earlier. The periapical condition was registered and compared by three observers in two series of intraoral radiographs taken 10-17 and 20-27 years after treatment. A retrospective analysis was performed to gain information about probable endodontic and nonendodontic reasons for extractions of lost roots, by evaluating their periapical status immediately after retreatment and at the 10-17-year follow-up.

RESULTS

Favourable outcomes were observed in 11 roots that had radiolucencies at the 10-17-year follow-up. Eight of these roots had periapical pathosis preoperatively, five of them filled with surplus root filling material. The percentage of cases recorded as normal condition at the final follow-up was 95.5%, including five cases initially recorded with increased width of the apical periodontal space. Delayed healing as a result of surplus root filling material explained most of the cases with favourable outcome assessed many years after treatment. Twenty-eight roots were lost because of extraction during the observation period, 17 during the last 10 years. Based on status at previous follow-ups, endodontic failure seems to represent a minor reason for extraction in the material.

CONCLUSION

Late periapical changes, with more successful cases, were recorded when a 10-17-year follow-up after root canal treatment was extended for another 10 years. Persistent asymptomatic periapical radiolucencies, especially those with overfill, should generally not be classified as failures, as many of them will heal after an extended observation period.

An evaluation of the usefulness of two endodontic case assessment forms by general dentists

AIM

To evaluate the use of two forms to assess the risks and difficulty of root-canal treatment.

METHODOLOGY

Two criterion-based forms, containing 15 and 16 items, respectively, were distributed to 83 general dentists to evaluate the potential difficulty of root-canal treatment. The participants were asked to assess the difficulty of 15 endodontic cases using the Dutch Endodontic Treatment Index (DETI) and the Endodontic Treatment Classification (ETC) forms. A questionnaire was also provided to evaluate the time needed to complete the two forms, their ease of use, the clarity and/or appropriateness of the criteria and any other comments. The outcomes of the assessment were compared with the assessment of each case as carried out by the authors.

RESULTS

The response rate was 53%. The DETI was an easy and rapid way to differentiate between uncomplicated and complicated cases. In 13 of the 15 cases, 88-100% of the dentists scored the cases in agreement with the authors. Use of the ETC form was more complicated, as a result of the larger number of variables. However, most respondents recognized the complicated cases, and 91% found the ETC form valuable to help in assessing the difficulty of endodontic cases.

CONCLUSIONS

These two forms may help general practitioners to assess the difficulty of endodontic problems and to decide whether to treat the case or to refer it to a specialist.

Endodontic infection: some biologic and treatment factors associated with outcome

OBJECTIVE

We sought to investigate the simultaneous effect of apical periodontitis, instrumentation level, and density of root canal filling on endodontic treatment outcome.

METHODS

For this study, 200 endodontically treated teeth with 441 roots were used. A follow-up examination was conducted 4 +/- 0.5 years postoperatively. Data were subjected to univariate and multivariate analysis.

RESULTS

Periapical pathosis had the strongest effect on treatment outcome (P <.0001). The instrumentation level (mean +/- SEM of the working length) for successfully treated teeth/roots with normal preoperative pulp and periapex was farther away from the radiographic apex (1.23 +/- 0.13 mm) than for teeth/roots with an unsuccessful outcome (0.20 +/- 0.09 mm; P <.005). However, successfully treated teeth/roots with pulp necrosis and apical periodontitis had working length levels closer to the radiographic apex (0.55 +/- 0.12 mm) than did teeth/roots with unsuccessful outcomes (1.73 +/- 0.30 mm; P<.001). In teeth/roots with apical periodontitis, a millimeter loss in working length increased the chance of treatment failure by 14%. The risk of failure was higher for a fair/poor density of obturation than for a good density for all diagnoses of periradicular status.

CONCLUSION

Diseased periapex, level of working length relative to the radiographic apex, and fair/poor density all affect the outcome of endodontic treatment.

Long-term survival of primary root canal treatment carried out in a dental teaching hospital

AIM

This study aimed to examine clinically and radiographically the survival of primary root canal treatment completed in a dental teaching hospital between 10 and 20 years previously.

METHODOLOGY

A data collection form was used to collate all information obtained from the written patients' records along with the results from clinical and radiographic examination of 608 teeth, out of a total of 986 randomly selected teeth that had been root filled in the Prince Philip Dental Hospital (PPDH), Hong Kong, between 1981 and 1989. The criteria for failure were extractions (except for documented nonendodontic reason), retreatments and presence of a periapical radiolucency. The survival function of the treated teeth was plotted against the calculated date of failure using the Kaplan-Meier (K-M) method. Covariables were examined further by Cox Regression analysis with a backward stepwise method.

RESULTS

A total of 314 teeth (52%) were either documented or deemed to have failed after examination. The median survival time was 111 months. Cox Regression analysis indicated that the survival of root-filled teeth was significantly influenced by the tooth type, preoperative periapical status and the type of coronal restoration. The survival function declined with time, with a rapid drop in the first 18 months or so. The rate at which failures occurred appeared to slow down with a longer observation time.

CONCLUSIONS

There was a nonlinear decline in the cumulative survival probability of primary root canal treatment. Tooth type, preoperative periapical status and type of post and final restoration significantly affected the long-term survival of the treated teeth.

Periapical changes following root-canal treatment observed 20-27 years postoperatively

AIM

The aim of the present study was to identify periapical changes 20-27 years after root-canal treatment.

METHODOLOGY

The periapical condition of 265 roots filled by undergraduate students was evaluated in two series of intraoral radiographs taken 10-17 and 20-27 years after treatment. Roots (72) not recorded with a normal periapical situation on both occasions by two observers, were re-evaluated by other two examiners, separately and jointly. Final decisions about diagnoses were made by all four examiners. A strict definition was used for the identification of cases with an unfavourable outcome.

RESULTS

Favourable outcomes were observed in 6.4% of the roots that had radiolucencies at the 10-17-year follow-up. Periapical radiolucencies after 20-27 years appeared in 1.5% of all other roots. The radiographic failure frequency for the total material was 4.9%. The percentage of cases with normal periapical findings at the final follow-up was 86.4%, whilst 8.7% were recorded with increased width of the apical periodontal space. Delayed healing owing to surplus root-filling material explained nearly all of the cases with favourable outcome assessed many years after treatment.

CONCLUSIONS

Late periapical changes, with more successes than failures, were recorded when a 10-17-year follow-up period after root-canal treatment was extended for another 10 years.

Diagnosing periapical lesions--disagreement and borderline cases

AIM

The aim of this paper is to present a selection of disagreement and borderline cases from a methodological study on the radiographic diagnosis of periapical disease.

METHODOLOGY

Thirty-two roots, 12% of the material in an earlier study, were subjected to joint discussion because of diagnostic problems. The aim was consensus. Six cases representing different teeth/roots illustrating typical problems are presented.

RESULTS

The varying morphology of apical areas and varying density of surrounding bone present a number of challenges. Even so, the joint discussion resulted in an agreement for all the cases. Twenty-five diagnoses were established and seven cases were not diagnosed owing to substandard radiographs.

CONCLUSION

A detailed analysis of the periodontal ligament space, the lamina dura, trabecular pattern and bone marrow spaces is mandatory for the radiographic diagnosis of periapical disease

Long-term reliability and observer comparisons in the radiographic diagnosis of periapical disease

AIM

The aim of this study was to evaluate and compare the long-term diagnostic consistency of two examiners, an endodontist and a radiologist, and to make comparisons with findings recorded by an observer with more recent scientific and clinical experience in endodontics.

METHODOLOGY

Three groups, each consisting of 20 full mouth series of intraoral radiographs, with 79, 93 and 85 endodontically-treated roots, respectively, were successively evaluated for periapical disease. Evaluations were at first performed separately by the three observers. Disagreement and difficult, borderline cases were subjected to joint evaluation. Intra- and interexaminer comparisons were made. For two of the observers the observations were compared with findings recorded several years before for the same cases in the same radiographs.

RESULTS

The intra- and interobserver long-term reliability of the two original examiners resulted in 83% overall agreement, the kappa values were 0.54, 0.57 and 0.53. Comparisons between all three observers disclosed 82%, 85% and 86% agreement and kappa values 0.55, 0.58 and 0.60. The joint evaluations and decisions did not indicate a dominating influence from any of the observers.

CONCLUSIONS

The long-term reliability of the two original observers was judged as being satisfactory. All three observers judged the overall disease status of the material in the same way. The joint discussions of selected cases might reduce observer variation to an acceptable level, avoid a number of false recordings and increase the reliability and validity of the findings.

Comparison of clinical outcome of periapical surgery in endodontic and oral surgery units of a teaching dental hospital: a retrospective study

OBJECTIVES

The aims of this retrospective study were (1) to compare the outcome of periapical surgery performed in endodontic and in oral surgery units of a teaching dental hospital and (2) to evaluate the influence of factors affecting outcome.

STUDY DESIGN

A total of 176 teeth (endodontic unit, 83; oral surgery unit, 93) surgically treated more than 4 years previously were examined clinically and radiographically by means of strict criteria. Multiple logistic regression analysis was used.

RESULTS

The rate of complete healing for patients treated in the endodontic unit (37.4%) was significantly (P = .009) higher than that for patients treated in the oral surgery unit (19.4%). The technical quality of surgery (P < .001), placement of root-end filling (P = .039), absence of a preoperative periapical lesion (P = .042), absence of a post (P = .047), and presence of an adequate coronal restoration (P = .056, odds ratio = 3.71) had significant effects on treatment outcome.

CONCLUSION

The technical quality of periapical surgery, the presence of a periapical lesion, and adequate apical and coronal seal are important prognostic determinants of successful periapical surgery.

A prognostic model for assessment of the outcome of endodontic treatment: Effect of biologic and diagnostic variables

OBJECTIVE

Many biological variables, endodontic treatment factors, and restorative considerations have been suggested in the literature to affect the outcome of endodontic treatment. However, few attempts have been made recently to study these variables further. The purpose of this study was to identify the biologic and endodontic treatment-associated variables that are most predictive of treatment outcome for conventional endodontic therapy and to determine the magnitude of risk these variables pose on the outcome.

STUDY DESIGN

The population of this historical prospective cohort study comprised a total of 200 teeth with 441 root canals. Diagnostic and treatment information was abstracted from the original patient records. An endodontic follow-up examination was conducted 4 +/- 0.5 years after obturation. Each tooth/root was analyzed according to 3 indices of periradicular status at 2 time points. The main outcome measure was the presence of apical periodontitis. The criteria used for evaluation of the outcome were modified from Strindberg. Data were subjected to univariate and multivariate analysis. Logistic regression models were fit by using various clinical measures to determine which combination of biologic and treatment-associated factors best predicted treatment outcome.

RESULTS

The preoperative pulp diagnosis, the periapical diagnosis, the preoperative periapical radiolucency size, and the sex of the patients were revealed, by means of univariate analysis, to exert a significant influence on endodontic treatment outcome (P <.05). In the logistic regression model, the strongest effect on postoperative healing was the presence and magnitude of preoperative apical periodontitis. In the presence of this variable, no other factor contributed value to the prediction. The correct prediction of this model was 74.7% (P <.05).

CONCLUSION

The major biologic factors influencing the outcome of endodontic treatment appear to be the extent of microbiological insult to the pulp and periapical tissue, as reflected by the periapical diagnosis and the magnitude of periapical pathosis.

Reliability of radiographic observations recorded on a proforma measured using inter- and intra-observer variation: a preliminary study

AIM

The aim of this preliminary study was to test the reliability of radiographic evaluation of features of endodontic interest using a newly devised data collection system.

METHODOLOGY

Twelve endodontic MSc postgraduate students and one specialist endodontist examined sample radiographs derived from a random selection of 42 patients seen previously on an Endodontic New Patient Clinic (EDI). Each student examined a random selection of 8-9 roots on periapical radiographs of single- and multirooted teeth, with and without previous root canal therapy and 3-4 dental panoramic tomograms (DPTs). A total of 100 roots were examined. A proforma was used to record observations on 67 radiographic features using predefined criteria. Intra-observer agreement was tested by asking the students to re-examine the radiographs. The principle investigator and the specialist endodontist examined the same radiographs and devised a Gold Standard using the same criteria. This was compared with the student assessments to determine inter-observer variation. The postgraduates then attended a revision session on the use of the form. Each student subsequently examined 8-9 different roots from the pool of radiographs. A further assessment of inter-observer variation was made by comparing these observations with the Gold Standard.

RESULTS

Of the 67 radiographic features, only 25 had sufficient response to allow statistical analysis. Kappa values for intra- and inter-observer variation were estimated. These varied depending on the particular radiographic feature being assessed. Fifteen out of 25 intra-observer recordings showed 'good' or 'very good' Kappa agreement, but only three out of 25 inter-observer observations achieved 'good' or 'very good' values. Inter-observer variation was improved following the revision session with 16 out of 25 observations achieving 'good' or 'very good' Kappa agreement.

CONCLUSIONS

Modification to the proforma, the criteria used, and training for radiographic assessment were considered necessary to improve the accuracy and reproducibility of the observations entered.

Outcomes of periradicular surgery in cases with apical pathosis and untreated canals

OBJECTIVE

Surgical management is intended to eliminate or block infection originating in the root canals. The root end is customarily sealed to prevent pathogenic products remaining in the root canal from reaching the periradicular tissues. The purpose of this study was to evaluate the microbiologic and radiographic outcomes of surgical treatment of periradicular pathosis associated with teeth with necrotic pulps.

STUDY DESIGN

One tooth from each of 10 patients was root-end resected and root-end filled without prior root canal treatment. One year postoperatively, the outcomes were assessed radiographically and the root canals were sampled for bacteria.

RESULTS

Radiographic examination showed complete or incomplete (scar tissue) healing in 5 teeth and uncertain healing in the other 5 teeth. Bacteriologic samples from the root canals were positive in 9 of the 10 cases.

CONCLUSIONS

In teeth with necrotic pulps, treatment of periradicular pathosis by surgery and root-end filling may show radiographic evidence of satisfactory healing 1 year postoperatively. However, viable bacteria may persist in the canals, constituting a potential risk factor for recurrence of periradicular pathosis.

Microbiologic analysis of teeth with failed endodontic treatment and the outcome of conservative re-treatment

OBJECTIVE

The purposes of this study were to determine what microbial flora were present in teeth after failed root canal therapy and to establish the outcome of conservative re-treatment.

STUDY DESIGN

Fifty-four root-filled teeth with persisting periapical lesions were selected for re-treatment. After removal of the root filling, canals were sampled by means of advanced microbiologic techniques. The teeth were then re-treated and followed for up to 5 years.

RESULTS

The microbial flora was mainly single species of predominantly gram-positive organisms. The isolates most commonly recovered were bacteria of the species Enterococcus faecalis. The overall success rate of re-treatment was 74%.

CONCLUSIONS

The microbial flora in canals after failed endodontic therapy differed markedly from the flora in untreated teeth. Infection at the time of root filling and size of the periapical lesion were factors that had a negative influence on the prognosis. Three of four endodontic failures were successfully managed by re-treatment.

Influence of infection at the time of root filling on the outcome of endodontic treatment of teeth with apical periodontitis

This study investigated the role of infection on the prognosis of endodontic therapy by following-up teeth that had had their canals cleaned and obturated during a single appointment. The root canals of 55 single-rooted teeth with apical periodontitis were thoroughly instrumented and irrigated with sodium hypochlorite solution. Using advanced anaerobic bacteriological techniques, post-instrumentation samples were taken and the teeth were then root-filled during the same appointment. All teeth were initially infected; after instrumentation low numbers of bacteria were detected in 22 of 55 root canals. Periapical healing was followed-up for 5 years. Complete periapical healing occurred in 94% of cases that yielded a negative culture. Where the samples were positive prior to root filling, the success rate of treatment was just 68%--a statistically significant difference. Further investigation of three failures revealed the presence of Actinomyces species in each case; no other specific bacteria were implicated in failure cases. These findings emphasize the importance of completely eliminating bacteria from the root canal system before obturation. This objective cannot be reliably achieved in a one-visit treatment because it is not possible to eradicate all infection from the root canal without the support of an inter-appointment antimicrobial dressing.