Effectiveness of diagnosing pulpitis: A systematic review.

BACKGROUND: The diagnosis of the status of the inflamed pulp is essential in clinical diagnosis and treatment provision. There are a limited number of well-designed and well-executed clinical trials on the diagnosis of the true status of the pulp. OBJECTIVES: Three PICO questions were formulated and agreed a priori by the European Society of Endodontology to evaluate the clinical tests for sensibility testing, determination of biomarkers and pulp bleeding with regard to their suitability to correctly diagnose the condition of the pulp tissue for the development of S3-Level guidelines. METHODS: A literature search was conducted using PubMed, Clarivate Analytics' Web of Science, Scopus, Google Scholar and Cochrane Central Register of Controlled Trials from inception to 21 January 2022. Additionally, a hand search was performed, and the contents of the major subject journals were also examined. Eligibility criteria followed the proposed PICO questions. Two independent reviewers were involved in study selection, data extraction and appraising the included studies; disagreements were resolved by a third reviewer. The risk of bias was assessed by the QUADAS-2 tool for diagnostic accuracy studies, the Newcastle-Ottawa scale for noncomparative, nonrandomized studies and the Newcastle-Ottawa Quality Assessment scale adapted for cross-sectional studies. RESULTS: In total, 28 studies out of 29 publications were considered eligible and were included in the review. Twelve studies were identified to investigate the diagnostic accuracy of the pulp vitality. Ten studies fulfilled the criteria to evaluate the diagnostic accuracy of the pulpal conditions, while 6 studies investigating the expression of biomarkers were eligible. Three studies addressing the prognostic factors and therapeutic interventions relating to pulpal status were included. DISCUSSION: The core problem in pulp diagnostics is that a reliable reference standard is lacking under clinical conditions. Based on limited evidence, the most promising current approach seems to define a combination of different clinical tests and symptoms, probably in future including molecular diagnosis ("diagnostic package") will be required to ascertain the best possible strategy to clinically diagnose true pulpal conditions. CONCLUSIONS: The effectiveness of diagnosing pulpitis is low due to limited scientific evidence regarding the accuracy and reproducibility of diagnostic tests. There is a lack of evidence to determine the true status of the pulp or to identify prognostic indicators allowing for a reliable pre-operative estimation of the outcome of vital pulp treatment. REGISTRATION: PROSPERO database (CRD42021265366).

A Pilot Feasibility Study to Establish Full Pulpotomy in Mature Permanent Teeth with Symptomatic Irreversible Pulpitis as a Routine Treatment in Mexican Public Healthcare Services.

Symptomatic irreversible pulpitis is a common dental disease for which root canal treatment (RCT) has been the standard treatment. However, in many countries, RCT is considered a high-cost treatment that is not covered by public healthcare services; this forces patients to have dental extraction as their only option to relieve pain. In the last decade, several investigations have provided evidence that an alternative treatment known as full pulpotomy (FP) could be an alternative for patients who could not afford the cost of an RCT. Nevertheless, evidence is lacking on the success rate that could be obtained if it is performed in a public dental care clinic (PDCC). The present investigation has two main objectives. To be the first approach of a multicentric feasibility study to find out whether an FP performed by a general practice dentist (GPD) in a PDCC could be suitable and establish its success rate and patient satisfaction. Patients attending a PDCC with symptoms of irreversible pulpitis were invited to participate. FP was performed and followed up at 1, 3, 6, 9, and 12 months. The treatment success was assessed by combining three variables, patient satisfaction, clinical, and radiographic outcomes. Forty-one patients from 17 to 78 years old received the intervention. In total, 97.5% were completely satisfied with the treatment and were considered successful since none of the clinical or radiographic variables were present in any of the follow-ups. An FP performed by a GPD in a PDCC could be suitable as a routine treatment for symptomatic irreversible pulpitis due to the excellent success rate and patient satisfaction.

Remineralization and protection from demineralization: effects of a hydroxyapatite-containing, a fluoride-containing and a fluoride- and hydroxyapatite-free toothpaste on human enamel in vitro.

BACKGROUND: The aim was to evaluate the remineralization potential as well as the extent of protection against renewed demineralization of enamel by hydroxyapatite-containing toothpaste (Karex) in comparison to fluoride-containing (Elmex) and fluoride- and hydroxyapatite-free toothpaste (Ajona) as control. METHODS: Fifty-seven enamel samples were obtained from 19 human teeth. Five demarcated surfaces were created on each tooth (S0-S4). Four of the surfaces (S1-S4) were exposed to lactic acid (pH 3) for 8 h (demineralization). S0 was left untreated as control. S1 was solely treated with acid. After demineralization, S2 was exposed to Karex for 2 min, of which 15 s were brushing. S3 was treated with Elmex and S4 with Ajona, accordingly. Then, the samples were evaluated using a scanning electron microscope and ImageJ image analysis software to determine the percentage of demineralization. Afterwards, S2-S4 were again exposed to lactic acid for 2 h, and subjected to pixel analysis another time. Data were statistically analysed using ANOVA with post-hoc Scheffé test and the Kurskal-Wallis test. RESULTS: The surfaces treated with Elmex showed the lowest percentage of demineralization (mean 5.01 ± 0.98%) (p < 0.01). Thus, Elmex remineralized more effectively compared to Ajona (8.89 ± 1.41%) and Karex (9.85 ± 1.63%) (p < 0.01). Furthermore, Elmex showed the lowest percentage of demineralized enamel after new demineralization (median 6.29%), followed by Ajona (11.92%) and Karex (13.46%) (p < 0.001). CONCLUSION: In terms of remineralization and protection against renewed demineralization, a hydroxyapatite-containing toothpaste (Karex) appears to be inferior to a fluoride-containing toothpaste (Elmex) and a fluoride- and hydroxyapatite-free toothpaste (Ajona). Hence, the recommendation to use Karex to protect against demineralization should be critically questioned.

Accuracy and reproducibility of the visualization of occlusal contact points using analog articulating foil or digital intraoral scanners in vitro.

AIM: The accuracy and reproducibility of occlusal contact points visualized by articulating foil (AF) were investigated and then compared with those calculated by three different intraoral scanners (IOSs). MATERIALS AND METHODS: Occlusal contact points were visualized on a standardized resin dental tooth model using AF 50 times in maximum intercuspation and with a constant biting force. The occlusal contact points were photographed from a vertical position above the model and superimposed on a screen to test the reproducibility of the model. This was followed by 50-fold repetition by scans and computation of the occlusal contact points by three different IOSs: CS 3600 (CS ScanFlow v.1, 4th version), Trios 3 (Basic 2019), and Cerec Omnicam (software version 5.1). The results of the computation were captured with screenshots and were then overlaid with the photographs of the AF. The image overlays were classified into five categories: 1 = total overlapping of contact points, 2 = partial overlapping of contact points, 3 = adjacent contact points without overlapping, 4 = contact points identified only by AF, 5 = contact points identified only by IOS. All data were statistically evaluated (95% confidence interval). RESULTS: In total, the visualization of the occlusal contact points by the IOSs were significantly less accurate and less reproducible compared with the AF (P < 0.05). When sensitivity and accuracy were combined, the Trios 3 (3Shape) showed significantly better results than the other IOSs tested (P < 0.05). CONCLUSION: In vitro, AF displayed a significantly more accurate visualization of the occlusal contact points than the IOSs.

Shear bond strength of CAD/CAM resin-based composite specimens to human dentin in comparison to CAD/CAM lithium disilicate ceramic specimens in vitro.

OBJECTIVES: The aim of this in vitro study was to compare the shear bond strength of a CAD/CAM resin-based composite restoration material with a lithium-disilicate-ceramic restoration material on human dentin. In addition, the influence of the chosen adhesive system should be investigated. METHOD AND MATERIALS: Thirty cylindrical specimens each were fabricated from the composite resin-based material Grandio Blocs (GB) and the ceramic IPS e.max CAD (IEM). In each case, 15 specimens were bonded to human dentin samples using the adhesive system recommended and provided by the manufacturer. For 15 additional specimens, the adhesive systems were interchanged. After water storage (4 weeks) and thermocycling (5,000 cycles between 5°C and 55°C), the shear bond strength, the fracture modes, and the Adhesive Remnant Index (ARI) were determined. All data were statistically evaluated (Kruskal-Wallis test; P < .05). RESULTS: The shear bond strength of IEM in combination with the manufacturer's recommended adhesive system was statistically significantly higher than in those of all other groups (P < .05), resulting in 39.24 ± 7.73 N/mm2. For IEM, adhesive fracture mode was the only mode found, while adhesive and mixed fracture modes occurred in both GB groups. Significantly more adhesive/restoration material remnants (ARI) remained on the dentin surfaces in both GB groups (P < .05). CONCLUSION: For IEM the adhesive system recommended by the manufacturer should be used. For the GB samples, the choice of adhesive system had no influence on the shear bond strength. With GB, fracture may occur partly within the material under heavy load.

Accuracy and reproducibility of the visualisation of occlusal contact points using analogue articulating foil or digital intraoral scanners in vitro.

AIM: The accuracy and reproducibility of occlusal contact points visualized by articulation foil (AF) should be investigated and then compared with contact points calculated by three different intraoral scanners (IOS). MATERIALS AND METHODS: Occlusal contact points were visualized on a standardized resin dental tooth model using AF 50 times with maximum intercuspidation and constant biting force. The points were photographed from a vertical position above the model and superimposed on a screen in order to test the reproducibility of the model. This was followed by fifty-fold repetition by scans and computation of the occlusal contact points by the respective IOS CS3600 (CS ScanFlow v.1 4th version), TRIOS 3 (Basic 2019), and CEREC Omnicam (Software version 5.1). The results of computation were captured with screenshots, and were then overlaid with the photographs of the AF. The image overlays were classified into five categories: category 1 = total overlapping of contact points, category 2 = partly overlapping, category 3 = adjacent contact points without overlapping, category 4 = contact points identified only by IOS, category 5 = contact points identified only by AF. All data were statistically evaluated (95% CI). RESULTS: In total, the visualisation of the occlusal contact points by the IOS were significantly less accurate and less reproducible compared to the AF (p < 0.05). In the combination of sensitivity and accuracy, the TRIOS3 by 3Shape showed significantly better results than the other IOS tested (p < 0.05). CONCLUSION: In vitro, AF displayed a significantly more accurate visualisation of the occlusal contact points than IOS.

Endodontic set sealer eluates promote cytokine production in human mononuclear and periodontal ligament cells.

Endodontic freshly mixed sealers display toxic effects; however, these are significantly reduced and most become relatively inert in the set state but there is no information about the possible inflammatory reaction promoted by them. Four contemporary and different formulated endodontic set sealers (MTA Fillapex, BioRoot RCS, AH Plus, and Pulp Canal Sealer) were evaluated. Human periodontal ligament cells and human peripheral blood mononuclear cells were stimulated for 3, 6, 12 and 24 h. Interleukin-6, tumour necrosis factor-alpha, interleukin-8 and interleukin-10 concentrations were measured by enzyme-linked immunosorbent assay. All endodontic set sealer eluates promoted a similar production (P ˃ 0.05) of the four cytokines. However, their concentrations decreased within a short time period to nearly undetectable concentrations after 24 h, suggesting that the studied endodontic set sealers do not possess inflammatory properties which has favoured their long-term use in clinical practice.

Restorative treatment in a case of amelogenesis imperfecta and 9-year follow-up: a case report.

BACKGROUND: Amelogenesis imperfecta is a hereditary malformation showing various manifestations regarding enamel dysplasia. This case report shows a 9-year follow-up after restorative treatment of a 16-year old female patient affected by a hypoplastic type of amelogenesis imperfecta. The caries-free, hypersensitive teeth of the patient were restored by direct dentin adhesive composite restorations performed in total etch technique. CASE PRESENTATION: After rehabilitation the patient reported a marked improvement of the mastication ability and quality of life especially during food intake. Accumulation of plaque was reduced and the ability to perform adequate oral hygiene was improved. During follow-up of 9 years recurring secondary caries and debonding of fillings were recognized and retreated. CONCLUSIONS: The retrospective assessment exhibits that the performed restorative treatment prolonged the time until further treatment has to be considered, such as prosthetic treatment.

Duration of Immersion and Type of Immersion Solution Distort the Outcome of Push-Out Bond Strength Testing Protocols.

This study aimed to investigate the influence of immersion duration and the type of immersion solution on the outcome of push-out bond strength (POBS) tests. Root canals of 120 straight single-rooted teeth were instrumented to a diameter of 1.5 mm and irrigated with 5 mL of 3% NaOCl. Four horizontal slices with a thickness of 1 mm were cut, representing the mid-portion of the root. The specimens (n = 480) were irrigated with 17% ethylenediaminetetraacetic acid(EDTA) for 60 seconds, then twice with distilled water (DW) for 30 s each. The canals were filled with either AH Plus (Dentsply Sirona, Konstanz, Germany) or BioRoot RCS (Septodont, St. Maur-des-Fossés, France) (n = 240). Separated into four groups per type of sealer (n = 60), the specimens were incubated at 37 °C covered with gauze moistened in DW or phosphate-buffered saline (PBS) for either one or eight weeks. Dislodgement resistance was measured and POBS was calculated. Statistical analysis was performed using the analysis of variance (ANOVA) test and the Student-Newman-Keuls test (p = 0.05). AH Plus showed higher POBS when stored in PBS compared to DW, irrespective of the incubation period (p < 0.05). BioRoot RCS displayed higher POBS when stored in DW compared to PBS after eight weeks of incubation (p < 0.05). No difference was found after one week of incubation (p > 0.05). Irrespective of the sealer or the immersion solution, POBS decreased from one week to eight weeks (p < 0.05). Mixed failure modes were found in all groups irrespective of sealer, immersion medium, or immersion period. POBS decreased after a longer incubation time in both immersion solutions. Duration of immersion and the type of immersion solution had a significant impact on the outcome of the POBS testing protocol.

Histological determination of cariously altered collagen after dentin caries excavation with the polymer bur PolyBur P1 in comparison to a conventional bud bur.

BACKGROUND: To compare the polymer bur PolyBur P1 (P1) with tungsten carbide bud bur H1 SE (H1) in removing cariously altered collagen during dentin caries excavation. METHODS: Fifty extracted teeth were split in the center of a carious lesion. The 100 specimens were randomly divided into 5 groups. Five dentists were asked to excavate 10 teeth each: one half with P1 and the corresponding half with H1. The time needed for caries excavation was measured. Subsequently, histological specimens were produced and analyzed by light-microscope after Mallory-Azan-staining. The thickness of remaining cariously altered collagen was measured (< 1 mm or > 1 mm). The results were statistically evaluated. RESULTS: The average time to excavate a cavity with P1 was 254 (± 148) sec and 202 (± 129) sec with H1. The difference in times was not statistically significant (p > 0.05). In the group P1 in 66.1% of the sections cariously altered collagen remained, whereas 33.9% showed sound collagen. In the group H1 45.7% sections had remaining cariously altered collagen and 54.3% showed sound collagen. The difference between P1 and H1 was statistically significant (p = 0.004). In the group P1 the layer of cariously altered collagen was significantly more often thicker than 1 mm than in the group H1 (p < 0.05). The variable "type of bur" had a statistically significant influence for the presence of cariously altered collagen (p = 0.003). CONCLUSIONS: Conventional H1 bud burs were significantly more effective in removing cariously altered collagen during dentin caries excavation than the polymer bur P1.

Histological evaluation of hard tissue formation after direct pulp capping with a fast-setting mineral trioxide aggregate (RetroMTA) in humans.

OBJECTIVES: To histologically evaluate the morphology of the newly formed mineralized tissue and of the adjacent cells, in intact human teeth subjected to mechanical pulp exposure and capping with a fast-setting mineral trioxide aggregate (RetroMTA). MATERIALS AND METHODS: Seven caries-free third molars from three adults were subjected to pulp exposure, direct capping with RetroMTA, and restoration with a composite resin. Seven months later, the teeth were clinically and radiographically evaluated, extracted, and subjected to histological processing and evaluation. RESULTS: All teeth were clinically and radiographically inconspicuous and showed no presence of severe inflammatory reactions. Bacteria were absent in all teeth. All cases exhibited some degree of mineralized tissue in the area of exposure to varying extent. This newly formed mineralized tissue was mostly atubular and did not display the features of regular dentine in any of the cases. No cells exhibiting the features of odontoblasts or odontoblast-like cells were observed. Instead, the cells exhibited a flat or cuboidal shape, resembling fibroblasts. CONCLUSIONS: When the exposed pulps were directly capped with RetroMTA, the new calcified hard tissue was not "regular dentine," and did not seem to be the product of genuine odontoblast differentiation. These results suggest that the formation of calcified tissues after direct pulp capping with RetroMTA may be more appropriately regarded as a reparative process than as a genuine regeneration response. CLINICAL RELEVANCE: This is the first histological study on humans showing that regular dentine was not regenerated when a bioactive pulp-capping material (RetroMTA) was placed over exposed pulp tissue. TRIAL REGISTRATION: NCT03631511.

Influence of the final irrigation solution on the push-out bond strength of calcium silicate-based, epoxy resin-based and silicone-based endodontic sealers.

The aim was to evaluate the influence of different irrigation solutions on the push-out bond strength (POBS) of three different sealers (AH Plus, BioRoot RCS, GuttaFlow2). Root canals of 180 single-rooted human teeth were instrumented with F360 up to size 45.04. All canals were irrigated with 5 ml NaOCl 3% and 5 ml EDTA 17%. The canals were finally irrigated with either 5 ml NaOCl 3%, CHX 2%, EDTA 17%, citric acid 20% or NaCl 0.9% (n = 36) with a contact time of 5 min and obturated using matching gutta-percha cones according to the single-cone technique in combination with one of the sealers (n = 12). After 8 weeks of incubation, the roots were embedded in resin. Two slices of 1 mm thickness were obtained representing the middle third of the root. Dislodgement resistance was measured and POBS was calculated. Specimens were examined under 4× magnification to determine the mode of bond failure. Statistical analysis was performed using two-way ANOVA and Student-Newman-Keuls test for POBS and Chi-square test for the mode of failure. POBS was significantly affected by the factor "sealer" (P < 0.001) and by the interaction "sealer/irrigation solution" (P < 0.01). AH Plus revealed significantly higher POBS than BioRoot RCS and GuttaFlow2 (P < 0.05). The POBS of GutttaFlow2 was not affected by the irrigation protocol (P > 0.05). The POBS of AH Plus was positively influenced by EDTA and NaOCl. EDTA had a negative effect on the POBS of BioRoot RCS. The POBS of GuttaFlow2 was not influenced by the irrigation solutions.

Evaluation of the biocompatibility of root canal sealers on human periodontal ligament cells ex vivo.

The aim of this study was to evaluate the biocompatibility of two comparatively new calcium silicate containing sealers (MTA-Fillapex and BioRoot-RCS) with that of two established sealers (AH-Plus, epoxy resin-based; Pulp-Canal-Sealer, zinc oxide eugenol containing). Human periodontal ligament cells (PDL-cells) were brought in contact with eluates from freshly mixed and set sealer. The sealers were mixed strictly according to the manufacturers' instructions and identically samples were produced. 1:1, 1:2, and 1:10 dilutions of sealers extract were used. Extracts from freshly mixed sealer were added to the PDL-cells on day one to simulate a clinical scenario. Subsequently, at 24 h, 7, 14, and 21 days extracts form set sealers were used for PDL-cell culturing. PDL-cell viability was analyzed by living-cell-count, MTT-assay, and living/dead-staining, cytotoxicity by LDH-assay, and changes by Richardson-staining. All data were statistically evaluated by one way ANOVA and a posthoc analysis with Bonferroni-Holm testing (p < 0.05). In contact with BioRoot-RCS a regeneration of the PDL-cells were observed over time. This sealer showed the lowest toxicity in a freshly mixed and set state (p < 0.05). MTA-Fillapex and Pulp-Canal-Sealer were cytotoxic in a fresh as well as in a set state, whereas AH-Plus was cytotoxic in a freshly mixed state, but not when the sealer was set. BioRoot-RCS is biocompatible and bioactive because it seems to have a positive influence on the PDL-cell metabolism. Pulp Canal Sealer and MTA-Fillapex showed no biocompatibility in contact with PDL-cells at all. Freshly mixed AH Plus is less biocompatible on PDL than in a set state.

Clinical evaluation of direct pulp capping using a calcium silicate cement-treatment outcomes over an average period of 2.3 years.

OBJECTIVES: This study aims to assess the treatment outcomes of direct pulp capping with a calcium silicate cement (Biodentine) after caries excavation. MATERIALS AND METHODS: A total of 245 teeth of 226 patients diagnosed to be clinical healthy or showing spontaneous pain were directly capped. The teeth were examined 0.19 to 7.4 (mean 2.3 ± 2.04) years after treatment. The following data were recorded: age and sex of the patient, type of tooth and restoration (glass ionomer cement [GIC], amalgam, composite resin, ceramic, gold) and symptoms before or after treatment. The evaluation of the treatment was carried out by sensibility and percussion testing and by the patient's questioning. A positive sensibility test, a negative percussion test, the absence of swelling and discomfort were considered as treatment success. Survival analysis was performed using the Kaplan-Meier, log-rank, Chi-square and Fisher's exact test, respectively. RESULTS: After an average period of 2.3 years, 86.0% of the teeth remained vital; the survival rate after 7.4 years was 83.4%. The treatment outcome was significantly worse for cavities restored with GIC compared to all other restorative materials (p < 0.05). All other evaluated factors had no significant influence on the success rate (p > 0.05). CONCLUSION: Exposed pulps of asymptomatic vital permanent teeth and teeth with spontaneous pain before treatment can be successfully capped directly using Biodentine. A subsequent restoration with GIC does not appear to be suitable as it significantly reduces the success of the treatment. CLINICAL RELEVANCE: Direct pulp capping can be done successfully with this type of calcium silicate cement.

Endodontic sealers based on calcium silicates: a systematic review.

Recently, sealers based on calcium silicates were developed as a new class of endodontic sealers. Inspired by the excellent sealing ability and biocompatibility of calcium silicate-based cements, these sealers establish a biological point of view on the obturation of root canals. No longer, the bacteria-tight seal against reinfection of the root canal is the only goal of root canal obturation. Antibacterial properties as well as bioactive inducement of periapical healing and hard tissue formation are added to the portfolio of sealers. Ready-to-use sealers consisting of only one component with a need for external water supply from, e.g., body fluid and two components sealers with internal water supply were introduced to the market. Both of these material types have the same setting reactions in common whereby a hydration reaction of the calcium silicate is followed by a precipitation reaction of calcium phosphate. Though the available sealers are all based on calcium silicates, they consist of different compositions. Due to this aspect, differences in their physical and chemical properties as well as in their in vitro characteristics were described. Studies addressing the clinical impact of calcium silicate-based sealers on outcome are still sparse. The bioactive potential of sealers based on calcium silicates is a consequence of the slight solubility of these materials even after setting, but solubility of the sealer might also compromise the quality of sealing a root canal against regrowth and reinfection. Further clinical investigations are required to evaluate the clinical relevance of the gulf between bioactivity and solubility.

Solubility and pH Value of 3 Different Root Canal Sealers: A Long-term Investigation.

INTRODUCTION: The aim of this study was to compare the solubility and the change in pH of a tricalcium silicate-containing sealer (BioRoot RCS [BR]), a mineral trioxide aggregate-containing sealer (MTA Fillapex [MTA]), and an epoxy resin-based sealer (AH Plus [AH]) during a longer period of time. METHODS: The solubility test was carried out in accordance with ISO6876:2012. Three hundred eighty sealer samples (n = 10 per group) were stored for 6 months in double distilled water (AD) or phosphate-buffered saline (PBS). The solubility was determined on the basis of the mass difference in percent. The pH measurement was carried out on the basis of the experimental setup of the solubility test with the aid of an electrode pH meter. The results were evaluated for significance by using analysis of variance, Student-Newman-Keuls, and t test (P < .05). RESULTS: The highest solubility was found for MTA in AD (4.65% ± 1.17%), followed by BR in AD (3.88% ± 0.42%) (P < .05). Also in PBS, MTA (3.24% ± 0.7%) showed a higher solubility than BR (1.78% ± 0.5%) (P < .05). AH was virtually insoluble during the entire period (0.5% ± 0.5%) (P < .05). The pH decreased continuously over time for all samples. After 6 months, BR showed the highest pH in AD (pH 10.3), followed by MTA in AD (pH 8.8), BR in PBS (pH 7.5), AH in PBS (pH 7.3), MTA in PBS (pH 7.2), and AH in AD (pH 6.3). CONCLUSIONS: The solubility of MTA was significantly increased compared with BR and AH. Storage in PBS significantly reduced solubility of MTA and BR. BR showed a higher pH in both AD and PBS than MTA in AD and PBS. AH did not cause any significant pH change.

The push-out bond strength of calcium silicate-based endodontic sealers.

BACKGROUND: The aim was to compare the dislodgement resistance of calcium silicate-based sealers (Total Fill BC Sealer, Endo CPM Sealer, BioRoot RCS) with an epoxy resin-based sealer (AH Plus). METHODS: The root canals of 80 single-rooted human teeth were instrumented with F360 up to size 45.04. All canals were obturated using matching gutta-percha cones according to the single-cone technique in combination with one of the mentioned sealers (n = 20 per group). After eight weeks of incubation (37 °C, 100% humidity), the roots were embedded in resin. Starting with a distance of 7 mm from the apex, four slices of 1 mm thickness were cut. Dislodgement resistance was measured using a universal testing machine and the push-out bond strength was calculated. Specimens were examined under 4×-magnification to determine the mode of bond failure. Statistical analysis was performed using ANOVA and Student-Newman-Keuls-test. RESULTS: Regarding the pooled data of all sections, the push-out bond strength of AH Plus was significantly higher than the push-out bond strength of all calcium silicate-containing sealers (P < 0.05). Out of all calcium silicate-based sealers, Total Fill BC Sealer showed the highest push-out bond strength (P < 0.05). BioRoot RCS had significant higher push-out bond strength than Endo CPM Sealer (P < 0.05). Nearly the same results were found for all four sections. BioRoot RCS only differed significantly from Endo CPM Sealer in the third section (P < 0.05). CONCLUSIONS: The push-out bond strength of the investigated calcium silicate-based sealers was lower than of AH Plus. Total Fill BC showed the highest push-out bond strength of the calcium silicate-based sealers.

Cytotoxic effects of four different root canal sealers on human osteoblasts.

The aim of this study was to evaluate the effect of an epoxy resin-based (AH-Plus), a zinc oxide eugenol containing (Pulp-Canal-Sealer) and two calcium silicate containing (MTA-Fillapex and BioRoot-RCS) sealers on primary human osteoblasts (hOB) in freshly mixed and set state. All sealers were mixed strictly according to the manufacturers´ instructions and identically samples were produced. In a pretest cytotoxic sealer concentrations were determined. Thus, for the main cell culture study, dilutions of sealer extract 1:1, 1:2, and 1:10 were used. To simulate a clinical scenario, extracts from freshly mixed sealer were added to the cells on day one. Extracts form set sealers were used for subsequent culturing for 24h, 7d, 14d, and 21d. Cell viability was analyzed by living-cell-count, MTT-assay, and living/dead-staining, cytotoxicity by LDH-assay, and changes by Richardson-staining. All data were statistically evaluated by one way ANOVA and a posthoc analysis with Bonferroni-Holm testing (p<0.05). AH-Plus was cytotoxic in a freshly mixed state, but not when the sealer was set. MTA-Fillapex and Pulp-Canal-Sealer were cytotoxic in a fresh as well as in a set state. BioRoot-RCS showed the lowest toxicity in both states; where as a regeneration of the cells could be observed over time (p<0.05). Contact of freshly mixed AH-Plus to osteoblasts should be avoided. Pulp Canal Sealer and MTA-Fillapex showed no biocompatibility in contact with osteoblasts at all. BioRoot-RCS had a positive influence on the cell metabolism (bioactivity) and is biocompatible.

Retreatability of three calcium silicate-containing sealers and one epoxy resin-based root canal sealer with four different root canal instruments.

OBJECTIVES: The objective of the study was to compare the retreatability of three calcium silicate-containing sealers (BioRoot RCS, MTA Fillapex, Endo C.P.M.) and an epoxy resin-based sealer (AH Plus) with different root canal instruments (Hedström files, Reciproc R40, Mtwo retreatment file R 25/.05 + Mtwo 40/.06, and F6 SkyTaper) concerning sealer remnants and retreatment time. MATERIALS AND METHODS: Root canals of 192 teeth were instrumented with Reciproc R40. All root canals were obturated using the single-cone technique with Reciproc R40 gutta-percha and one of the sealers (n = 48 per sealer). Two months later, retreatment was performed using one of the mentioned instruments (n = 12 per instrument and sealer). The roots were split longitudinally, and both halves were investigated using light microscopy. The percentage of sealer remnants covering the root canal wall was evaluated using the software ImageJ. The time required for retreatment was recorded. Statistical analysis was performed using two-way ANOVA and Student-Newman-Keuls post hoc test. RESULTS: Regarding the percentage of root canal filling remnants as well as retreatment time, two-way ANOVA indicated that the results were significantly affected by the sealer (p < 0.001) and by the instrument used (p < 0.05). Overall, the use of AH Plus was associated with significantly more remnants compared to all other sealers (p < 0.001) and F6 SkyTaper instruments allowed significantly faster retreatment than the other instruments (p < 0.05). CONCLUSION: The retreatability of calcium silicate-containing sealers was better compared to AH Plus as less sealer remnants and shorter retreatment times were observed. Retreatment with engine-driven NiTi instruments was superior compared to hand instrumentation. CLINICAL RELEVANCE: Engine-driven NiTi instruments are better suited to remove root canal fillings than stainless steel Hedström files.

Shear Bond Strength of Lining Materials to Calcium-silicate Cements at Different Time Intervals.

PURPOSE: To compare the shear bond strength of three different light-curing, flowable composites (Ionoseal [IS], Vertise flow [VF], and Futurabond NR + Grandio Flow [GF]) on MTA-Angelus [MTA] or Biodentine [BD] at three different time intervals. MATERIALS AND METHODS: Freshly mixed MTA or BD was applied into 180 identical plaster molds. Three minutes, 15 min, and 2 days after mixing, specimens of IS, VF, and GF with standardized size and diameter were applied on MTA and BD specimens (n = 10 per material and time interval). Subsequently, all specimens were stored at 36°C and 100% humidity for 28 days. The shear bond strength was determined using a universal testing machine. Statistical evaluation was performed using multifactorial ANOVA and post-hoc Tukey's Test (p < 0.05). RESULTS: Multifactorial ANOVA did not show any significant influence of the combinations "lining material × time" (p = 0.257) and "calcium-silicate cement × lining material × time" (p = 0.241). Significant influences were detected for the interactions "calcium-silicate cement × lining material" (p = 0.000) and "calcium-silicate cement × time" (p = 0.009) and for the parameters calcium-silicate cement (p = 0.000), lining material (p = 0.000), and time (p = 0.008). The predominant failure mode of the restorative materials to the cement surfaces was mixed. CONCLUSION: Already 3 min after mixing, IS, VF, and GF achieved shear bond strengths on MTA or BD that were similar to those after 15 min and 2 days.