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.

Protocols for cleaning the incisor access cavity contaminated with epoxy resin sealer.

This study compared different methods for cleaning the sealer-contaminated access cavity of upper incisors. After standard endodontic access, the canals of 50 extracted maxillary incisors were chemomechanically prepared and obturated with gutta-percha and epoxy resin sealer. Teeth were randomly assigned to one of five different pulp chamber cleaning protocols (n = 10): air/water spray, ethanol-saturated cotton pellet (CP), ethanol-saturated microbrush reaching the root filling (MB), MB + air polishing (PROPHYflex; KaVo), or MB + etching with 37% phosphoric acid. Each tooth was split and the sealer-covered area of the pulp chamber was determined on images taken before and after cleaning using image analysis software. The sealer-covered area was compared across groups using one-way ANOVA. Greatest mean sealer-covered area reduction was observed for MB + etching (98.0%), MB + air polishing (95.2%), and MB alone (92.8%), yielding a significantly higher sealer-covered area reduction than after air/water spray (8.3%) and ethanol-saturated cotton pellet (53.4%). The upper incisor access cavity is best cleaned with an ethanol-saturated microbrush reaching up to the root filling, followed by air/water spraying and etching. The use of cotton pellets should be discouraged.

Antibiotics at replantation of avulsed permanent teeth? A systematic review.

OBJECTIVES: At present there is no clear consensus whether systemic antibiotics should be administered at replantation of an avulsed permanent tooth. This systematic review and meta-analysis assessed the evidence on effectiveness and harms of the administration of systemic antibiotics at replantation of avulsed permanent teeth. METHODS: In August 2020 a systematic literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, for systematic reviews, randomized controlled trials (RCT) and observational controlled studies in MEDLINE, PreMedline, Embase, and the Cochrane databases. The population of interest were medically fit patients with a replanted avulsed tooth. Main outcomes were tooth survival, periodontal healing, pulpal revascularization as well as (severe) adverse events. These outcomes were compared in patients who did and who did not receive systemic antibiotics. The GRADE methodology was used to assess the quality of evidence. RESULTS: The search yielded no RCTs, and none of the 7 included observational studies had the prime intent to investigate the effectiveness or harms of antibiotics. According to GRADE, the overall level of evidence was very low. The meta-analyses showed non-significant associations between the administration of systemic antibiotics on the one hand and tooth survival (1 study, RR = 3.70, 95% CI: 0.63-21.69), periodontal healing (meta-analysis of 6 studies RR: 1.07; 95% CI: 0.80-1.45), and pulpal revascularization (meta-analysis of 2 studies, RR: 0.36; 95% CI: 0.05-2.41) on the other hand. CONCLUSION: Currently there is no high-quality evidence to support the use of systemic antibiotics at replantation of avulsed permanent teeth. Hence, their routine use cannot be recommended in medically fit patients. Well-designed RCTs should be a priority on the research agenda.

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.

Adjunctive Steps for the Removal of Hard Tissue Debris from the Anatomic Complexities of the Mesial Root Canal System of Mandibular Molars: A Micro-Computed Tomographic Study.

INTRODUCTION: This in vitro study sought to compare the efficacy of a sonic irrigant activation device with ultrasonic activation and needle irrigation in removing hard tissue debris (HTD) from anatomic complexities of the root canal system. METHODS: Twenty-seven mesial roots of extracted human mandibular molars with 2 canals connected by an isthmus were selected based on micro-computed tomography scans (12-µm voxel size). The mesial canals were mechanically prepared to ProTaper Next X3 (Dentsply Maillefer, Ballaigues, Switzerland) and anatomically distributed into 3 groups (n = 9) according to the final irrigation protocol: sonically activated irrigation (SAI) using the EDDY system (VDW GbmH, Munich, Germany) for 3 × 20 seconds, ultrasonically activated irrigation (UAI) using a size 20 Irrisafe tip (Satelec Acteon, Mérignac, France) for 3 × 20 seconds, and conventional irrigation using a 30-G needle adapted to a syringe. Micro-computed tomographic scans were taken after instrumentation and after supplementary activation of the irrigant. After reconstruction and coregistration, the volume filled with HTD before and after irrigant activation was calculated, and the mean percentage of HTD reduction after final irrigation was compared within and among groups using the paired sample t test and 1-way analysis of variance post hoc Tukey test, respectively (α = 5%). RESULTS: A significant reduction in the volume filled with HTD after irrigant activation was observed in all groups (P < .05). The percentage reduction of HTD in the UAI group (66.8%) was significantly higher than that in the SAI group (36.4%) (P < .05), whereas the conventional irrigation group result (43.7%) did not differ statistically from the UAI or SAI groups (P > .05). CONCLUSIONS: All tested supplementary irrigation steps significantly reduced the amount of debris created during root canal preparation. Ultrasonic activation resulted in the highest mean debris reduction.

Debris Removal from the Mesial Root Canal System of Mandibular Molars with Laser-activated Irrigation.

INTRODUCTION: The purpose of this study was to compare in vitro the canal and isthmus debridement of manual-dynamic, passive ultrasonic, and laser-activated irrigation with an Er:YAG laser in mesial roots of human mandibular molars. METHODS: Fifty extracted mandibular molars with an isthmus were embedded in resin and sectioned axially 4 mm from the apex. The teeth were reassembled with guide pins and bolts, and the mesial canals were instrumented up to a ProTaper F2 rotary file (Dentsply Maillefer, Ballaigues, Switzerland). Teeth were randomly assigned to the following irrigant activation groups (n = 10): conventional needle irrigation (NI), manual-dynamic irrigation with a ProTaper F2 gutta-percha cone, ultrasonically activated irrigation using a size 20 Irrisafe (Satelec Acteon, Mérignac, France), and laser-activated irrigation (LAI) with an Er:YAG laser and a conical 400-µm fiber tip in the canal entrance or a 600-µm tip over the canal entrance. Root cross-sectional images were taken before and after final irrigation, and the area occupied by debris in the main canal and the isthmus was determined using image analysis software. Differences in debris before and after activation were statistically compared within and across groups. RESULTS: Significant reductions in debris levels were observed in all groups, except for NI and manual-dynamic irrigation (canal only). None of the methods rendered the canal systems debris free. In the canal, LAI with an Er:YAG laser and a 600-µm tip over the canal entrance removed significantly more debris than NI. In the isthmus, LAI with an Er:YAG laser and a conical 400-µm fiber tip in the canal entrance removed significantly more debris than NI. CONCLUSIONS: Within the limitations of this in vitro study, canal and isthmus cleanliness significantly improved after irrigant activation.

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.

Insight in the chemistry of laser-activated dental bleaching.

The use of optical radiation for the activation of bleaching products has not yet been completely elucidated. Laser light is suggested to enhance the oxidizing effect of hydrogen peroxide. Different methods of enhancing hydrogen peroxide based bleaching are possible. They can be classified into six groups: alkaline pH environment, thermal enhancement and photothermal effect, photooxidation effect and direct photobleaching, photolysis effect and photodissociation, Fenton reaction and photocatalysis, and photodynamic effect.

Laser teeth bleaching: evaluation of eventual side effects on enamel and the pulp and the efficiency in vitro and in vivo.

Light and heat increase the reactivity of hydrogen peroxide. There is no evidence that light activation (power bleaching with high-intensity light) results in a more effective bleaching with a longer lasting effect with high concentrated hydrogen peroxide bleaching gels. Laser light differs from conventional light as it requires a laser-target interaction. The interaction takes place in the first instance in the bleaching gel. The second interaction has to be induced in the tooth, more specifically in the dentine. There is evidence that interaction exists with the bleaching gel: photothermal, photocatalytical, and photochemical interactions are described. The reactivity of the gel is increased by adding photocatalyst of photosensitizers. Direct and effective photobleaching, that is, a direct interaction with the colour molecules in the dentine, however, is only possible with the argon (488 and 415 nm) and KTP laser (532 nm). A number of risks have been described such as heat generation. Nd:YAG and especially high power diode lasers present a risk with intrapulpal temperature elevation up to 22°C. Hypersensitivity is regularly encountered, being it of temporary occurrence except for a number of diode wavelengths and the Nd:YAG. The tooth surface remains intact after laser bleaching. At present, KTP laser is the most efficient dental bleaching wavelength.

Investigation of Coronal Leakage of Root Fillings after Smear Layer Removal with EDTA or Er,Cr:YSGG Laser through Capillary Flow Porometry.

No studies have been performed evaluating the marginal seal of root fillings after direct exposure of root canal (RC) walls to Er,Cr:YSGG laser irradiation. Therefore, 75 root filled teeth (5 × 15-cold lateral condensation) were analyzed for through-and-through leakage (TTL) using capillary flow porometry (CFP). The cleaning protocol determined the experimental groups: (1) irrigation with NaOCl 2.5% and EDTA 17% or standard protocol (SP), (2) SP + Er,Cr:YSGG lasing (dried RC), (3) NaOCl 2.5% + Er,Cr:YSGG lasing (dried RC), (4) SP + Er,Cr:YSGG lasing (wet RC), and (5) NaOCl 2.5% + Er,Cr:YSGG lasing (wet RC). Groups 6 to 10 consisted of the same filled teeth with resected apices. Resection was performed after the first CFP measurement. CFP was used to assess minimum, mean flow, and maximum pore diameters after 48 h. Statistics were performed using nonparametric tests (P > 0.05). Additional three roots per group were submitted to SEM of the RC walls. TTL was observed in all groups without statistically significant differences between the different groups for minimum, mean, and maximum pore diameter (P > 0.05). In this study, the use of EDTA and/or Er,Cr:YSGG laser did not reduce through-and-through leakage in nonresected and resected roots.

Investigation of coronal leakage of root fillings after smear-layer removal with EDTA or Nd:YAG lasing through capillary-flow porometry.

OBJECTIVE: This study investigates the effects of Nd:YAG laser irradiation combined with different irrigation protocols on the marginal seal of root fillings. BACKGROUND DATA: Limited information exists regarding the effects of morphologic changes to root canal (RC) walls after Nd:YAG laser irradiation after smear-layer removal with EDTA on the sealing ability of root fillings. METHODS: The 75 root-filled teeth (5 × 15 teeth) were analyzed for through-and-through leakage by using capillary flow porometry (CFP). The RC cleaning procedure determined the assignment to a group: (1) irrigation with NaOCl 2.5% and EDTA 17% or standard protocol (SP), (2) SP + Nd:YAG lasing (dried RC), (3) NaOCl 2.5% + Nd:YAG lasing (dried RC), (4) SP + Nd:YAG lasing (wet RC), or (5) NaOCl 2.5% + Nd:YAG lasing (wet RC). Groups 1r to 5r consisted of the same filled teeth with resected apices up to the most apical point of the preparation length. Resection was performed after the first CFP measurement. Roots were filled with cold lateral condensation. CFP was used to assess minimum, mean flow and maximum pore diameters after 48 h, and immediately after these measurements, including root resection. Statistics were performed by using nonparametric tests (p > 0.05). An additional three roots per group were submitted to SEM of the RC wall. RESULTS: Through-and-through leakage was observed in all groups. Statistically significant differences were observed in maximum pore diameter: 1r > 3r, and 1r > 5r; in mean flow pore diameter: 1r > 2r, 2r < 4r (p < 0.05). Typical Nd:YAG glazing effects were observed when the smear layer was present and exposed to the laser fiber (i.e., in the groups without use of EDTA) or when the fiber tip made direct contact with a smear-layer free RC wall. CONCLUSIONS: The reduction in through-and-through leakage is significantly higher with the Nd:YAG laser as smear-layer modifier than when smear layer is removed with an EDTA rinsing solution.

Microleakage of glass ionomer formulations after erbium:yttrium-aluminium-garnet laser preparation.

The aim of this study was to investigate the microleakage in class V cavities restored with four conventionally setting glass ionomers (CGIs) and one resin-modified glass ionomer (RMGI) following erbium:yttrium-aluminium-garnet (Er:YAG) laser or conventional preparation. Four hundred class V cavities were assigned to four groups: A and B were prepared by an Er:YAG laser; C and D were conventionally prepared. In groups B and D, the surface was additionally conditioned with Ketac conditioner. Each group was divided into five subgroups according to the glass ionomer cement (GIC) used: groups 1 (Ketac Fil), 2 (Ketac Molar), 3 (Ionofil Molar), 4 (Ionofil Molar Quick) and 5 (Photac Fil Quick). After thermocycling, a 2% methylene blue solution was used as dye. Scanning electron microscope (SEM) photographs were taken to show the conditioner's effect. Complete marginal sealing could not be reached. PhotacFil showed less microleakage than the conventionally setting glass ionomer cements (CGICs) investigated. Conditioning laser-prepared cavities did not negatively influence microleakage results except for Ionofil Molar Quick.

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.

Microleakage of four different restorative glass ionomer formulations in class V cavities: Er:YAG laser versus conventional preparation.

OBJECTIVE: To investigate microleakage in class V cavities following restoration with conventional glass-ionomer cements (CGICs) or resin-modified glass-ionomer cements (RMGICs), following Er:YAG laser or conventional preparation. BACKGROUND DATA: The sealing ability of GICs in Er:YAG-lased cavities has not been studied extensively. METHODS: Three hundred and twenty class V cavities were assigned to four groups: those in groups A and B were prepared using an Er:YAG laser, and those in groups C and D were conventionally prepared. In groups B and D the surface was additionally conditioned with cavity conditioner. Each group was subdivided according to the GIC used: groups 1 (Fuji II), 2 (Fuji IX), 3 (Fuji II LC) and 4 (Fuji VIII). After thermocycling, the specimens were immersed in a 2% methylene blue solution, sectioned oro-facially, and analyzed for leakage. The effect of the conditioner was analyzed using a scanning electron microscope (SEM). RESULTS: Significant differences between occlusal and gingival margins were found in all groups (p < 0.05) except B4, D3, and D4. Comparison of preparation methods (groups A-D) revealed significant differences at the occlusal margin in groups 1 and 3, but in all groups at the gingival margin (p < 0.05). Laser preparation without conditioning allowed more leakage (p < 0.05). Comparison of filling materials (groups 1-4) revealed significant differences in groups B and C at the occlusal margin, and in all groups at the gingival margin (p < 0.05). In these groups, laser-prepared cavities (with or without conditioning) restored with Fuji II LC and Fuji VIII showed the least leakage at both margins. CONCLUSION: RMGICs allowed less microleakage than CGICs. Complete marginal sealing was not achieved and conditioning is recommended.

[Dental and buccal complications of lip and tongue piercing]. / Complications dentaires et buccales des piercings labiaux et linguaux.

Oral and facial piercing with different kinds of body art are being observed more frequently in medical and dental practices. Principally, piercing is not a new form of body art and is traditional in different geographical areas. In this review, the possible risks and complications are described. Postprocedural complications are oedema, haemorrhage and infection. Other adverse outcomes include mucosal or gingival trauma, chipped or fractured teeth, increased salivary flow, calculus build-up, and interference with speech, mastication and swallowing. Dentists, and oral- and maxillofacial surgeons should be in the position to advise patients with orofocial piercings or those who plan to have this type of body art performed.

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]. / Analyse critique des etudes sur la percolation en endodontie.

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.