A 22-year follow-up cross-sectional study on periapical health in relation to the quality of root canal treatment in a Belgian population

AIM

To investigate the prevalence of apical periodontitis (AP) and the technical standard of root canal treatment in a Belgian population, assess the association of different variables with periapical status, and compare the results to a similar study conducted 22 years previously.

METHODOLOGY

In this cross-sectional study, 614 panoramic radiographs of first-time adult attendees at the Dental School of the University Hospital of Ghent were examined. Recorded patient-level parameters included gender, age, number of teeth, number of root filled teeth, presence of any AP lesion, and number of implants. The following tooth-level data were collected: tooth presence, coronal status, quality of coronal restoration, post presence, type of root-filling material, length and density of root filling, root-end filling material, presence of AP, and adjacent implant. Multivariable multilevel binary logistic regression was used to explore the association between patient and tooth characteristics and AP prevalence. Risk differences and confidence intervals were calculated to compare the present with the previous study.

RESULTS

The prevalence of AP at patient and tooth level was 46.9% and 5.6%, respectively. Fifty-one per cent of the 614 patients had at least one root filled tooth, and 5.9% of the 14 655 teeth studied were root filled. AP was found in 45% of root filled teeth. Fifty-four per cent of the root-filled teeth were rated as inadequate. Multivariable multilevel logistic regression revealed that more teeth, more implants, fewer root-filled teeth, adequate density, adequate coronal restoration, and no caries reduced the likelihood of AP. There were no statistically significant differences between the two studies regarding the prevalence of root-filled teeth or AP and the technical quality of root canal treatment.

CONCLUSIONS

The prevalence of AP and the technical quality of root canal treatment in Belgium have not substantially changed over the last 22 years, despite the technological advancements and continuing education in the field.

Comparative efficacy of materials used in patients undergoing pulpotomy or direct pulp capping in carious teeth: A systematic review and meta-analysis

OBJECTIVES

Different materials have been used for capping the pulp after exposure during caries removal in permanent teeth. The purpose of this study was to collate and analyze all pertinent evidence from randomized controlled trials (RCTs) on different materials used in patients undergoing pulpotomy or direct pulp capping in carious teeth.

MATERIALS AND METHODS

Trials comparing two or more capping agents used for direct pulp capping (DPC) or pulpotomy were considered eligible. An electronic search of four databases and two clinical trial registries was carried out up to February 28, 2021 using a search strategy properly adapted to the PICO framework. Screening, data extraction, and risk of bias (RoB) assessment of primary studies were performed in duplicate and independently. The primary outcome was clinical and radiological success; secondary outcomes included continued root formation, tooth discoloration, and dentin bridge formation.

RESULTS

21 RCTs were included in the study. The RoB assessment indicated a moderate risk among the studies. Due to significant clinical and statistical heterogeneity among the studies, performing network meta-analysis (NMA) was not possible. An ad hoc subgroup analysis revealed strong evidence of a higher success of DPC with Mineral Trioxide Aggregate (MTA) compared to calcium hydroxide (CH) (odds ratio [OR] = 3.10, 95% confidence interval [CI]: 1.66-5.79). MTA performed better than CH in pulp capping (both DPC and pulpotomy) of mature compared to immature teeth (OR = 3.34, 95% CI: 1.81-6.17). The GRADE assessment revealed moderate strength of evidence for DPC and mature teeth, and low to very low strength of evidence for the remaining subgroups.

CONCLUSIONS

Considerable clinical and statistical heterogeneity among the trials did not allow NMA. The ad hoc subgroup analysis indicated that the clinical and radiographic success of MTA was higher than that of CH but only in mature teeth and DPC cases where the strength of evidence was moderate. PROSPERO Registration: number CRD42020127239.

Do stool types have an influence on cervicothoracic muscle activity and cervicothoracic posture among dentists/dental students?

It has been shown that the type of stool influences lumbar posture and muscle activity during dental work. Studies investigating the effect on cervicothoracic muscle activity and posture are scarce though. The present study investigated the effect of different stool types on cervicothoracic muscle activity and posture during a dental procedure. Twenty five participants completed a simulated periodontal screening whilst sitting on the Ghopec, Salli MultiAdjuster saddle and A-dec dental stool. Muscle activity of M. Splenius Capitis, M. Sternocleidomastoideus, M. Trapezius Pars Descendens and M. Trapezius Pars Ascendens was measured using surface electromyography. Cervicothoracic posture was evaluated by means of a strain gauge (BodyGuard™) fixed between C5 and T2. No differences in muscle activity and posture were found between the three stools. Although the type of stool influences lumbar posture and muscle activity, it seems these differences are not continued at the cervicothoracic region.

Influence of a calcium hydroxide-based intracanal dressing on the quality of the root canal filling assessed by capillary flow porometry

OBJECTIVE

The objective of this study is to evaluate the influence of a calcium hydroxide intracanal dressing (CH) on the short- and long-term sealing ability of the root canal filling using capillary flow porometry (CFP).

MATERIALS AND METHODS

To verify the repeatability of the method, five obturated specimens were submitted to CFP. Measurements were repeated three times and compared with the non-parametric Friedman test. Forty-five instrumented palatal roots were randomly divided into three groups. Group 1: specimens were obturated in one step without placement of any dressing. Group 2: CH was placed and removed after 1 week with syringe irrigation before obturation. Group 3: CH was placed and removed after 1 week with ultrasonic activation before obturation. CFP measurements were conducted at 1 week and 6 months after obturation. The inter-group comparisons were performed using the Kruskal-Wallis test and the intra-group comparison over time using the Wilcoxon signed-rank test. Significance level was set at 0.05.

RESULTS

In the five specimens, no difference could be detected between the consecutive measurements for minimum, mean flow, and maximum pore diameter indicating repeatability of the method. No difference in sealing ability could be detected neither between the 3 groups at 1 week and at 6 months nor within each group between the 1 week and the 6 months measurements.

CONCLUSIONS

Placement of a CH did not affect significantly the short- and long-term sealing ability of the root canal filling.

CLINICAL RELEVANCE

The use of an intermediary CH does not negatively influence the quality of the root canal filling.

Influence of different stool types on muscle activity and lumbar posture among dentists during a simulated dental screening task

Whereas in the past dental stools typically facilitated a 90° hip angle, a number of currently available alternative designs allow for a more extended hip posture. The present study investigated the influence of different stool types on muscle activity and lumbar posture. Twenty five participants completed a simulated dental procedure on a standard stool, a saddle and the Ghopec. The latter stool comprises a seat pan consisting of a horizontal rear part for the pelvis and an inclinable sloping down front part for the upper legs, with a vertically and horizontally adjustable back rest. Lumbar posture was most close to neutral on the Ghopec, whereas sitting on a standard/saddle stool resulted in more flexed/extended postures respectively. Sitting with a 90° angle (standard stool) resulted in higher activation of back muscles while sitting with a 125° angle (saddle and Ghopec) activated abdominal muscles more, although less in the presence of a backrest (Ghopec). To maintain neutral posture during dental screening, the Ghopec is considered the most suitable design for the tasks undertaken.

Influence of cracks on leakage and obturation efficiency of root-end filling materials after ultrasonic preparation: an in vitro evaluation

OBJECTIVES

To evaluate (1) the apical seal of root-end cavities using mineral trioxide aggregate (MTA) and glass-ionomer cement in teeth with and without cracks after ultrasonic root-end preparation and (2) the obturation efficiency of the materials in the root-end cavities.

METHOD AND MATERIALS

Sixty teeth with root-end cavities were divided into 3 groups: teeth without cracks (-) (group A) and teeth with cracks (+) (group B). The third group (4 teeth) served as a control. Groups A and B were each divided into 2 subgroups: Groups 1A and 1B were filled with Fuji IX capsules (GC) after treatment with cavity conditioner; groups 2A and 2B were filled with white MTA (Dentsply). The teeth were immersed in india ink and cleared. Apical leakage was measured from the resection surface to the maximal point of ink infiltration. Obturation efficiency was scored as good (acceptable), irregular (acceptable), or poor (unacceptable). Statistical analysis was performed using nonparametric and Fisher exact tests.

RESULTS

Apical leakage could be arranged in the following order: Fuji IX+ > MTA+ > Fuji IX- > MTA-. Significant differences between Fuji IX- and Fuji IX+ (P < .001) and between MTA- and MTA+ (P < .001) were demonstrated. Fuji IX showed significantly more unacceptable fillings than did MTA (P < .005). No correlation between obturation efficiency and apical leakage was demonstrated (P > .05).

CONCLUSION

The presence of cracks originating from the root canal negatively influences the seal of root-end filling materials and is probably of major clinical importance. MTA and Fuji IX showed equal sealing capacity, but MTA showed better obturation efficiency in the root-end cavity than Fuji IX.

Capillary Flow Porometry to Assess the Seal Provided by Root-End Filling Materials in a Standardized and Reproducible Way

This in vitro study evaluated the root-end sealing ability of gutta-percha + AH26 (GP), Ketac-Fil, Fuji IX (FIX), tooth-colored MTA (MTA), IRM, Ketac-Fil + conditioner (Ketac-FilC), and Fuji IX + conditioner (FIXC). A total of 140 standardized bovine root sections were divided into seven groups, filled with the mentioned root-end filling materials, and, at 48 h, submitted to capillary flow porometry to assess minimum, mean flow and maximum pore diameters. Results were statistically analyzed using nonparametric Kruskal-Wallis and Dunn tests. Level of significance was set at 0.05. Using the Kruskal-Wallis tests we found that there was no significant difference between the minimum pore diameters of the different materials, but significant differences between the mean flow (p < 0.001) and maximum (p < 0.001) pore diameters could be demonstrated. For the mean flow pore diameters, there was a significant difference between FIX and all other materials, between Ketac-Fil and IRM and between Ketac-FilC and IRM. Concerning maximum pore diameters, there was a significant difference between FIX and all other materials, between Ketac-Fil and MTA, GP and IRM, FIXC and IRM, and Ketac-FilC and IRM. The data showed that each sample had leaked. Glass ionomer cements leaked more than other materials, although dentin conditioning diminished the maximum through pore diameters. This maximum pore diameter, which corresponds to the largest leak in the sample, together with the size of bacteria and their metabolites, will be indicative of the eventual leakage along the root-end filling materials.

[Critical analysis of leakage studies in endodontics]

Incomplete filling of the root canal is one of the major causes of endodontic failure. Endodontic filling techniques and materials which perfectly seal the canal are essential for the success of endodontic treatment. Different in vitro tests are being used to test the sealing efficiency of endodontic filling techniques and materials. A large amount of these tests are leakage tests which measure the penetration of a tracer along the root canal filling. Tracers mainly are dyes, radio-isotopes, bacteria, bacterial metabolites, fungi and others. Apart from the tracer penetration techniques there are also other techniques. The electrochemical technique measures electrical current passing through the void along the root canal filling. The fluid transport method evaluates through-and-through voids along the canal filling. With this technique pressure on the water at the coronal side of the root canal filling is increased. In case of leakage, this will be registered based on the movement of an air bubble in a capillary attached to the end of the root. All of the described methods have their limitations. The largest limitations are the low reproducibility of some of the methods and the absence of standardization. Capillary flow porometry, a method well-known from the industry, has recently been applied in dentistry. With this method through pores can be evaluated in a standardised and reproducible way. Voids which do not extend along the entire root canal filling still have to be evaluated with other methods. Despite of the shortcomings of the in vitro leakage tests, they remain useful as an initial screening of new materials and techniques for canal obturation.

The long-term sealing ability of AH 26 and AH plus used with three gutta-percha obturation techniques

OBJECTIVE

To evaluate and compare the sealability of root fillings in extracted teeth by using AH 26 and AH Plus in conjunction with three different obturation techniques.

METHOD AND MATERIALS

Root canals of 940 single-rooted teeth were prepared according to the crown-down/stepback technique (using both 2.5% NaOCl and File-Eze) before lateral condensation and hybrid condensation of gutta percha or obturation with Thermafil. Teeth were immersed in India ink for 90 hours after storage for 1 day, 1 week, 2 weeks, 1 month, and 6 months. The roots were split longitudinally, and the extent of dye penetration was measured using a stereomicroscope. Statistical analysis was performed using Kruskal-Wallis test and Mann-Whitney U test.

RESULTS

There were no statistically significant differences in apical leakage within the AH 26 and the AH Plus groups, nor between the two sealer groups, at any observation period. Coronal leakage was significantly higher for Thermafil compared to hybrid condensation at 1 day, 1 week, and 2 weeks both for AH 26 and AH Plus. Coronal leakage was higher only for Thermafil compared to lateral condensation at 1 week for AH 26 and for lateral condensation compared to hybrid condensation at 1 week for AH Plus.

CONCLUSION

Both AH 26 and AH Plus, when used with an identical gutta-percha obturation technique, resulted in comparable sealability at all evaluation times and in comparable coronal sealability at 1 and 6 months.